MPN: iBirdie Black Hot Tub Cover 85 x 67. Model Number: iBirdie Black Hot Tub Cover 85 x 67. Manufacturer Part Number: iBirdie Black Hot Tub Cover 85 x 67. Manufacturer: iBirdie. Well Made: iBirdie Hot Tub cover is made of heavy-duty fabric with a waterproof coating; All seams are double-stitched for strength and have a sealant attached to the seams to prevent tears, leaks, etc.