Set of 4 High tensile steel custom made cylinder stud for all TAYLOR engines These studs are machined from quality British engineering steel and tapped 13mm one end and 17mm the other. This enables you to adjust the available length of the stud when screwed into the case by turning it upside down Short engines like the 40/46/55/65 will use the studs with the longer tapped end fully screwed into the case. Where longer stroke engines will fit it reverse.