Set of 10. This model is designed specifically for use with pedal steels. The shortened string post and bushing are designed for the slotted head of a pedal steel. It will house a headstock thickness varying from .235” (5.97mm) to .400” (10.16mm). The string post extends .900” (22.87mm) from the base of the housing. The housing has a mounting pin at the back, eliminating the need for a mounting screw. This also facilitates mounting on the cast headstocks used on pedal steel guitars.