Best used as a replacement part for a breather vent cork for a Cobra brand kayak. When a kayak is rotationally molded hot air must escape from the mold. A vent is placed in the mold for this purpose. This leaves a hole in the kayak’s deck and it must be filled. Vents are sealed with this cork and some hot glue at the factory. Use any quality adhesive sealant. These plugs are NOT meant to removed, and often are damaged in the process. We imagine this is why you are getting one now. These plugs are previously installed in kayaks and removed from kayaks that have had a cargo hatch installed at the breather vent location.UT