Extreme Grip: Our special manufacturing process enables our suction cups with knurled nuts to hold firmly and permanently on smooth surfaces such as tiles, windows and walls, or outdoors or bathrooms Easy to Install: No drilling, no screws, just clean the bracket, press down and fix with knurled nuts. Product details: 20 large suction cups. The actual suction cup size is 40mm. Each cup can hold up to 2 kg. Versatile usage: Our suction cups can vacuum on all smooth surfaces, such as windows and glass, tiles, plastic, Formica and more. Pack of 20 Suction Cups with 40mm M4 Thread - Clear Suction Cups with Knurled Nuts. Due to the vacuum effect, they have a powerful suction and are suitable for fixing: + all kinds of hanging signs: office signs, bus signs, advertising posters+ in the caravan: for attaching light objects+ in the kitchen or bathroom: as Towel rack for soap in the shower.Your advantages at a glance:Extremely versatile.unparalleled persistenceVery high absorbency.Quick and easy to assemble. Quantity: 20 pieces