When you’re installing tile you want to cut holes for fixtures in the right place the first time. There are several ways to do this pretty accurately: measuring the location and transferring the measurements to the tile, placing the tile over a previous tile and using another tile to transfer the location of the hole, or making a template out of cardboard.
Compared to the above methods, Kapro’s 303 ceramic hole marker is just a faster reusable template. You can use it to copy the positions of pipe holes right onto tile. Slip the closed hole over a pipe stub and align the handle with the corner of the installed tile, tighten the screw lock, and transfer the measurement to your tile.
Kapro likens their 303 ceramic tile hole marker to a T-bevel with the addition of a hole at one end and a half-hole at the other with inner radii of 32mm (1.25″) and outer radii of 75 mm (2.95″). They manufacture the blade from PVC and mark it in both inches and centimeters. They construct the handle from fiberglass reinforced polymer and give it markings on the handle every 15°. A right angle wing on the handle allows you to align the tool repeatedly.
Given the specific use of this tool, it’s hard to imagine anybody but a professional installer purchasing it, but it’s a relatively cheap investment of as little as $8 before shipping.