Duncan
Sorry can't help with the connector but I have found the tyre depth gauge simple to use and for quick checks good enough accuracy, you do need to make a better foot so the gauge is stable when in use.
1 advantage in use is I don't have to jog the work from under the spindle to gain access to check depth measurements, it's much shorter than a 6" Mitutoyo Digital caliper and a Mitutoyo mechanical 0-25mm depth gauge but these are used for final checks.
Emgee
Edited By Emgee on 10/12/2021 00:22:57