This a flex filament connector for SPC serial ports commonly found on digital calipers and indicators, for those wanting to build a DIY DRO or simply read the data off the calipers over serial.

Update: check out #EspDRO which uses an ESP32 and this connector to stream this data over WiFi and serial: https://github.com/MGX3D/EspDRO. Video of it in use: https://www.youtube.com/watch?v=P8z91OxXOTo

Note it's designed for a really tight fit:I recommend printing this out of flexible filament (TPU) only. It seems to work quite well for this purpose. I might be biased, but this little thing seems to work better than the flimsy commercial connectors that came with my DRO (which I was hesitant to cut the cable to reuse and thus I ended up down the rabbit hole of designing this thing). It's also shorter than commercial connectors, it only sticks out 10mm, and the ribs on the side and top help with the grip when unplugging.

To assemble: you only need some 24AWG wire (0.4-0.6mm diameter wire, with 1.2-1.4mm sleeve diameter). Works with both solid wire and stranded (w/ solder coating for the contact area). Strip about 20mm of wire, wrap it around the tip, tighten it and cut the excess, then tuck it in (you can add a dab of super-glue but seems to work fine even without).