These wedge-shaped scupper plugs are specific to Crescent Kayaks and will likely fit other sit-on-top brands--please measure your scupper holes first. The plugs are designed to push and turn into place, much like a corkscrew, to keep water from entering through the scupper hole into the cockpit from the underside of a Crescent Kayak. Ordering Considerations: The Standard variant is sold as a pair and fits all Crescent models, including the cockpit of the UltraLite; it does not fit the UltraLite tankwell. The starting end (base) of the plug (the narrowest point) is 1 3/8" wide. The UltraLite Tankwell specific variant is sold as a unit of 1; it is a smaller plug that fits the tankwell of this model only. The starting end of this plug is 1" wide.