PN#032020 SKU#12091 In-Line Quick Release Valve. 1-1/2″ diameter x 3-1/2″ long, Mounts at Tractor Gladhand. Speeds up release of trailer service brakes when installed on service side gladhand. Speeds up release of trailer parking brakes when installed on emergency side gladhand. Suitable for use on double or triple trailers. Durable zinc die cast bodies. Flow Rate: Forward – 9.0 SCFM at 2 psi; Exhaust – 8.0 SCFM at 2 psi. 1/2″-14 MPT with Vibraseal thread sealer on one end, 1/2″-14 FPT other end. 1-1/2″ diameter x 3-1/2″ long.