Automotive Internal Protrusion Check Gauge (ECER21)

Need a light weight protrusion height gauge to do some benchmark?
Here it is.
This gauge has a Ø165 ball head, with Ø50 cylinder to measure the protrusion height according to ECER21.
If the protrusion is 3.2mm, the half core with 3.2 mark will be even with bottom;
If the protrusion is 9.5mm, the half core with 9.5 mark will be even with bottom.

Assemble:
Glue the 2 half core ruler together with some fillament segments as pins, cut some silicone rubber to the size of 12x4x3 and insert them into the 3 slots of Ø50 cylinder to get some smooth friction, and put the core ruler into the hole.