The Railbolt Drill Guide is perfectly suited for the Zipbolt UT Railbolt 13.600 and can also be used with adjustment for the Angled Railbolt 11.550 and now all the Slipfix models (13.801,13.950,13.900) where boring onto the rail/fitting is needed. It will make the job of boring accurately into the end grain of rails and fittings much easier, please follow instructions as to the set back distance of the 25mm/1" hole as this varies between different models.