About this item. Smooth surface application:: Our suction cups can be sucked on all smooth surfaces such as windows and glass, ceramic tiles. But the water may cause it to fall off. Easy to organize: : The wire and the provided transparent knurled nut make it easy to organize the kitchen accessory space and make a furniture installation of craft or hold decorations etc. Dimensions: : diameter: 40mm, height of M5 thread: 10mm. Quantity: : 8 pieces. Good after-sales service: If you have any problem with our suction cups, please feel free to contact us.