Adjustable Inner Groove Caliper Tips

I've seen a few models for tips to allow calipers to measure the inside of objects with a rim. None of them are adjustable, however, so I made this. The pegs should friction fit with PLA. Without any pegs, the attachments add 3mm each. There are pegs for 5mm, 10mm, 15mm, and 20mm. If these don't fit your calipers, please let me know, I'll add a variant.