The Ultralift Undermount conversion kit allows for you to change your standard cover lift into one with an undermount. With this undermount, there is no more drilling into the side of your spa to install a cover lifter. This is bought in addition to a Ultralift cover lifter.
Thumbscrew 1/4 - 20 x 1.75 inch. These are used to secure your corner skirting pieces on your spa in place. This part is the longer of the two thumb-screws available.