Gems DF series Warrick dual function control with screw mount standoff. Dual function series DF models are designed to control two independent level functions, one single-level control operation and one differential-level operation. Applications include dual function, single-level service, differential service, feedwater control/low-water cutoff, high level/low level, pump down/high level. 26K ohms direct sensitivity, 120 VAC voltage. U.L. 508 file #E44426 approvals. Measures 4-3/8" width by 2-1/2" height.