KEEPNUT press-in self-anchoring inserts by Specialinsert is a revolutionary press-in anchor insert used for a number of applications including undermount sink installation, ventilated facades, cladding, and furniture. These small inserts are designed to install into a wide range of surfaces including granite, marble, quartz, solid surface, HPL, glass, fiber cement, and other compact materials. The solid surface insert's small size also lends itself to be installed into extremely thin surfaces while also being extremely strong. In addition, the Keep-Nut press-in self-anchoring insert is manufactured in stainless steel and it's made of a threaded bush with a set of elastic crowns and a plastic ring for holding the complete set of parts together