Fast deliveries
Wide range of products
Favourable prices

Spalock also called thermolock

At Kuben you can buy the best spalock on the market, sometimes called thermolock, made of the highest quality to withstand the Swedish climate. Sannra spalock has a high density and thickness of 127 mm with a case of premium marine vinyl. The spalock is available in several colours, grey, brown and black and in stock for the most common models. We also customise the spalock for most hot tubs on the market. Free home delivery is included in the price as well as a 2-year warranty. 

Find the right spalock right here!

Enter the dimensions of your spa and quickly find your new spa cover for immediate home delivery.

Start by choosing the shape of your hot tub

Rectangular / Square


A-Side (mm)
B-Side (mm)
Horn radius (mm)
Diameter (mm)

Our spalock


We have lids in stock for most brands on the Swedish market. Our spalock is built to withstand wind, rain and cold for many years. A heavy snow cover should not be able to deform the lid, while rainwater should run off automatically.

Spalocket should be as smooth and easy to handle as possible, while maximising insulation and minimising heating costs.

Based on the above criteria in combination with our almost 20 years of experience of hot tubs, we have continuously developed what has resulted in one of the market's absolute highest quality and popular Spalock.

We build our spalock with the utmost care in every detail and therefore provide a 2 year warranty.

Home delivery takes 1-3 days and is done with DHL and of course we have open purchase 30 days. Read more.

Spalock 215 x 215 R=15.2 mm Grey for Artesian, Catalina and K-rauta etc.
sannraweb e1558356617295

How do I measure my hot tub?

  • NOTE! Always measure on the bath and not on your spalock. You will receive information on how to measure after choosing the type of spalock.
  • A spa cover can always be a little bigger than the spa. An extra couple of centimetres just makes it easier to place on the spa.
  • The lid of a spa can therefore always have a smaller radius than the spa.
  • The skirt also hangs down 120 mm so any overhang is rarely visible.
Play Video about spalock measure

Key buying tips for buying a cover for your hot tub

Product sheet and specification.

Construction details

Thickness of insulation block highest part
The thickness (cut) and high density provide good insulating properties.
5 inches (about 127 mm) is a good value, which still keeps the weight of the lid manageable.
Thickness of insulation block lowest part
Should be slightly lower than the highest point to allow for water run-off. 4 inches (approx. 102 mm).
Density of insulation blocks
The higher the density the better. 25 kg / m³ is a good value.
Reinforcement of the centre section
Steel superior to aluminium in strength and torsional rigidity. 2 x galvanised steel U-beam.
Placed by reinforcement
Avoid recessed reinforcements that can easily damage the vapour barrier. Embedded in the insulation block.
Type of vapour barrier
Plastic film coated with aluminium. Superior moisture and chemical barrier. Vacuum sealed, and hot welded.
Insulation in the centre joint

Often there are only 2 small cushions at the outer edge of 
the centre joint of a spalock, which means unnecessary heat losses.
Case material

Every spalock from us is made of Marinvinyl Premium. 
Swedish Guarantee

2 years Guarantee according to specification
Open purchase

30 days
Shipping cost

Free home delivery with DHL

1 - 3 days

Learn more about our hot tub covers

Constructions consists of insulating blocks with a density of 25 kg per cubic metre and is reinforced by a galvanised steel U-beam (steel is superior to aluminium in strength and torsional rigidity) embedded in the insulating block so that it cannot damage the moisture barrier. The moisture barrier is in turn vacuum-sealed, hot-welded and made of aluminium-coated plastic film.

The function of the vapour barrier and importance of a spalock is worth commenting on further. One of the most common problems with spalock is that the vapour barrier fails and the cover takes in water and soon weighs 150 kg. The vapour barrier is therefore extremely important. We therefore decided to offer the most reliable vapour barrier on the market and we are convinced that we have now achieved this.

The moisture barrier is made of Mylar, which is a material made of specially treated polyester and aluminium foil. The cost of this material alone represents more than 15% of the total cost of the cover, but it's worth it! Ask our 1000s of satisfied customers over the years!

Marine vinyl which wraps the entire structure is of the highest quality and is anti-UV and anti-mildew treated at the factory. Finally, for maximum durability, the joint of the vinyl is insulated along the entire length of the spalock with 2 small and one long pad to create durability and minimise heat loss.

Order measurements

We manufacture customised spalock in all shapes and sizes. 

Square, rectangular, round or oval spalock, spalock with one or more cut corners. If you have a correct drawing, you can customise your lid at We manufacture the lid exactly according to your drawing in the same fantastic quality as our stocked standard lids. Expect approx. 10-12 weeks delivery time. For a square or rectangular spalock, we only need the A side, B side and corner radius to quote.  

Click here to get in touch with us regarding Customised Spalock. Only when the lid is delivered from our warehouse does a signal go to Klarna, which sends an invoice, 14 days net, to you. This means that you have had the lid for about 10 days before it is time to pay. Safe for you and for us. 

Heavy duty spalock

Snow, ice or water on the spalocket?

The spalock has a slope that allows water to drain automatically. A smaller slope from side to side contributes to this effective drainage function. Snow and ice are best removed manually. However, don't panic if some snow remains on the lid. The spalock is robustly constructed. See picture; "a picture says more than 1000 words"?

Of course, we do not recommend that a spa cover be subjected to unnecessary stress and that you walk on it unnecessarily, or place heavy objects on top of it. Quite the contrary. But with the picture above, we still want to highlight the fact that there is a difference in construction and quality between a spa cover from Sannra and A good spa cover should perform well for a long time.

bottom hub

The base fabric

The bottom fabric is an additional protective layer on the underside of a spalock. The primary purpose of the fabric is to protect both the insulation block and the vapour barrier against harmful chemicals and, not least, cracks. The construction should of course also last a long time so that the spalock does not need to be replaced within just a few years. With these criteria in mind, we have chosen to manufacture our Sannra lids with a premium solution in the form of a multi-laminated vinyl base, which we are extremely satisfied with. It takes a relatively large external impact on the lid for an unwanted tear to appear on the spalocket. Original lids and cheaper aftermarket lids rarely offer this type of construction, but usually consist of a marine vinyl that over time deteriorates significantly in performance when in contact with the spa water.


The quality of the stitching naturally affects the life of the spalock. Our spalocks are constructed with a double-twisted polyester thread that is basically "tireless". If cheaper designs and materials are chosen, there is a risk that the handle and stitching will fail over time. Concerns about similar mishaps are unwarranted when buying our Sannra™ spalock.


Our YKK manufactured zips on the Sannra™ spa lid are designed for heavy duty products. These heavy-duty zips are resistant to corrosion, rust and resist contact with chemicals from the spa.


We mainly stock Spalock in the colours grey, black, brown and light grey. When ordering made-to-measure, it is of course possible to choose any colour. The delivery time for customised Spalock is approx. 3 months under normal circumstances and no money is paid in advance. 



Light grey

Light grey






Dark brown

Questions and answers

Do you need an answer to your specific question?

Check our FAQ

Do not hesitate to contact on 018-240900 or via email at [email protected]! We look forward to you contacting us with your questions and concerns.

Contact us

Sales, returns, complaints, delivery and support

(+46) (0)18 – 24 09 00
( Swedish support )
Weekdays 09:00 - 11:30
[email protected]