This template is produced under license and is officially authorized by Robin Fitton, the author of "Gruntz 15mm"™ and it bears the official Gruntz logo..
Template includes edges that are 1", 2", 3", and 4" long for measuring. It includes one reference 45 degree angle, and two diameter templates, one at 1" and one at 2".
Template is made from durable 1/16" (1.5mm) clear acrylic (AKA Plexiglass or Persplex)
