Description: Rubber gasket set that is installed on the watch back case,can cover the gap between the watch band Play role in watch waterproof,suitable for watch repair and DIY watchmaker 10 different sizes from 16 to 30 mm:14, 15, 16, 17, 18, 19,24, 28, 32 and 33mm. Comes 50pcs each size in a poly bag (total: 50pcs x 10 = 500pcs) Material: Rubber Package Includes: 500 Pieces Washers O Rings Seals