Specially designed for water cooled 4-strokes with 16mm plugs. 2-step extension - Swivel or Fixed. Socket can be used with a screwdriver to hold the front 19mm hex axles of late model 4-strokes. For use on models like KTM 4-strokes, DRZ400, CRF450R, YZF/WRF400/426, YZF250, KLX300, DVX400 HD and more.