a small bushing for door knocker on my 1995 GMC van, although it should work for many similar age chevy/gmc vehicles. it is a bit difficult to get on, but once it is it works very well.

helps with rattling/ poorly closing doors 

printed mine in PLA, standard settings

higher infill -> harder to install but more durable
lower infill -> easier to install but less durable

you'll have to find a balance that works for you