Our Neoprene Well Nuts feature high quality rubber and brass nuts. The screw rod is preferably made of stainless steel. The above materials have good rust and resistance, suitable for your long-term use. Using for Pozidriv screws, the "well nuts" can be easily inserted into the pre-drilled holes until the flange is firmly seated against the mounting . Threading the threaded screw into the brass nut expands the insert for a secure hold. We have three sizes of rubber well nuts: M5 M6. Removable screw anchors are suitable for a variety of applications in a variety of situations. Perfect for kayaks, canoes, boats and other marine applications. Material: Rubber + Brass colour: Black Package Contents: 12 x well nut with screws 20mm 12 x M5 well nut with M5 screws 25mm 12 x M6 well nut with M6 screws 30mm Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.