Just a probe command that uses 24.7mm as the thickness of the probe. It’s a “double-tap” probe to, hopefully, improve accuracy. First two commands don’t cause motion. The g38.2 will probe and stop on contact, then it will lift 2mm and probe again, slowly. On that probe, it will set the Z height at 24.7mm. Retract so you can get the probe out.
Same commands CM uses for a probe (not sure if they double-tap).