Spa Fitter
Alps Spas K2 Replacement Cover
The Alps Spas K2 takes the AIRCAP 1™ Large — a foam-free replacement hot tub cover for square spas 89"–91". The K2's cabinet measures 90" x 90", inside the Large's range. The cover weighs 35–40 lb for life, costs $1,195, is engineered to comply with ASTM F1346-23, and carries a 3-year limited warranty.
| Spa cabinet | 90" x 90" |
|---|---|
| AIRCAP 1™ size | Large fits 89"–91" |
| Cover weight | 35–40 lb — constant for life |
| Price | $1,195, free US shipping |
| Skirt | Ziptech™ modular, three lengths included |
| Safety | Engineered to comply with ASTM F1346-23 |
| Warranty | 3-year limited warranty |
Why the Large fits the K2
The AIRCAP 1™ comes in six sizes covering square spas from 77" to 94". Each size is built to overhang its band slightly — that is how a spa cover is meant to sit — so the Large, which fits cabinets 89"–91", covers the K2's 90" x 90" shell with the right overhang. Instead of a rigid foam core wrapped in vinyl, the AIRCAP 1™ uses welded drop-stitch construction (the material of premium inflatable paddleboards): a sealed air chamber that cannot absorb water, so it never becomes the waterlogged, two-person lift that ends most foam covers.
Cabinet dimensions can change between model years. Before ordering, measure your K2 side to side across the top of the cabinet in both directions — the SureFit™ guide walks through it in two measurements. If your spa measures between two sizes, round up.
Other Alps Spas models we fit
Not a K2?
The Spa Fitter matches 363 models across 25 brands to the right AIRCAP 1™ — or measure any square spa with SureFit™.