Fits a 66mm or less wide common sharpening block. Fixed at 17 degrees for easy operation. Very hard edge knives can take a 15 degree edge, cheaper common ones last longer at 20mm. 17 is a compromise angle used by many for a wider variety of kitchen knives. Designed to slide along the block base while holding the knife at the angle. Holes to help grip. Feet/sliders widened so you can use without the common rubber bumper without sliding into the gap removing it leaves behind. 

Made this because other holders were 60mm wide (too snug) and did not slide on the base like I anted this to. Think of it as a useful training device to holding that angle.

Warning; It takes a long time to get a 20 degree edge to be a 17 degree edge. But it's worth it.