Blue Wave NP5043 Easy-Off Deluxe Spa Cover Lift Hydraulic lift design for effortless spa cover removal; Fits square, rectangular, octagon, oval and most round spas Does not attach to spa cabinet preventing damage to spa; Quick and easy setup - pre-assembled to save time Heavy duty powder-coated metal tubing for superior strength & long-lasting corrosion resistance Lifter adjusts from 16" to 21" to accommodate different cover thickness Lifter arms fold flat when not in use