Made for the “With Voltage Regulator” type of ADXL345 boards like shown in the Klipper docs.
https://klipper.discourse.group/t/raspberry-pi-pico-adxl345-portable-resonance-measurement/1757
It mounts to a volcano heater block by unscrewing the nozzle completely and adding this mount in between nozzle and block.
A picture showing how, is posted in the comments!
The author marked this model as their own original creation.