ITEM NAME:10x suction cup Ø 40mm with M4 thread, suction cups, with knurled nut cle U 3C And clear knurled nut. Suction cups transparent, diameter 40 mm, For fixing signs etc. on smoo th Surfaces, such. Glass, tiles, etc. M4 threaded pin with 6 mm length. The suction cups are made with a high quality, transparent.And clear knurled nut. M4 threaded pin with 6 mm length. Knurled nut supplied (no simple, soft "whites").