This is a mount to fix a Tuya Temperature and Humidity Sensor (model WSD400B/TS0201) to a Trinity brand wire rack.
The Trinity wire rack I have is a "TRINITY EcoStorageā¢ 4-Tier Wire Shelving Rack | 48" x 18" x 72" | NSF | Includes Wheels | Chrome" from Costco. Which I believe is a very common design, features 31mm tall frontside.
Check out my related model for a human presence sensor: https://www.printables.com/model/531538-tuya-human-presence-sensor-wire-rack-mount
The author marked this model as their own original creation.