Generalaire 3610 Filter Restrictor Indicator Gauge (F.R.I. Gauge)
Features:
•FRI (K) 30" Vacuum Filter Restriction Indicator.
•Threads into the top of Gar-Ber filters to let you know if & when your filter needs to be changed.
•High readings indicate the filter cartridge needs to be replaced.
•Copper alloy C-Shape Bourdon Tube
•Spring suspended movement
•Mounts directly to General Adapter Head or at fuel unit
•1-1/2" Diameter Dial
•30” Hg. Vacuum Filter Restriction Indicator
•Colored easy-to-read dial
•Available with all models
•1/8” NPT male