The park tool hcw 11 adjustable cup wrench fits slotted bottom bracket adjusting cups and cups with raised 16mm wrench flats these are common on older english bicycles and less expensive bicycles the opposite end has two ears that are 23mm wide and approximately 5mm wide park tool hcw 11 adjustable cup wrench features double ended tools save space in the workshop 16 mm slotted and raised open end double pin lockring end suitable for older style bottom bracket