Size:about 8mm in width,you can choose diameter size (please dont use your image to judge size,1-2 mm allowable error)
Size Reference 6 size=16mm in diameter 7 size=17mm in diameter 8 size=18mm in diameter 9 size=19mm in diameter 10 size=20mm in diameter 11 size=21mm in diameter 12 size=22mm in diameter 13 size=23mm in diameter