2.88 inch hole spacer
I made this to precisely mark the 12-mm holes needed to put a 50-ct string of Rextin WS2811 addressable RGB LED lights into a 12-foot length of 5/8" or 3/4" vinyl siding J-channel, for mounting onto my house.
This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/9eistODLIYS