The cap is made of high quality plastic, strong and durable.
There are 11 sizes, decreasing by the diameter(mm): 21.8/19.8/18.8/17.8/16.9/15.7/14.8/13.6/12.7/11.6/9.8, 5pcs each size.
Screw thread with slotted connector.
It is replacement parts, can be used for most motors, match with rotary hammer, grinding machine, electric saw, electric grinder, cutting machine, trimming machine etc.
Please make sure enough space for holding carbon brush