Basic Bridle Rings have 1.5" long threaded stand off as stated per the National Electrical Code.  Bridle Rings can be used to secure various wiring cables including fire alarm, HVAC, thermostat, etc.

1 1/4" Bridle Ring

1/4-20 Thread

2" Bridle Ring

1/4-20 Thread

4" Bridle Ring

1/4-20 Thread