[Dewy]

Outside of easier math, it strikes me the 1-1/2" (37.5 MM?) should be capable of most of the jobs using template guides that the 40 MM guide will do. Granted not all bits will fit but there is ample clearance for the collet and swarf removal. Since the 40 MM guide is not available isn't this a viable alternative for North American members?

Quick lesson in metric conversion.
1½" = 38.1mm not 37.5

¼" = 6.35mm
1" = 25.4mm
½" = 12.7mm
¾" = 19.05mm