This unique can tap has an R-134a screw on can connection and a R12/R22 service port connection. It was made for EnviroSafe cans which have an R-134a thread and allows you to install directly to R12 and R22 systems. Centrally installed is an easy to read pressure gauge. 20" long hose 1/4" end end fits R12, 22, 502 fittings Gauge has scale readings for R134, R12, & 22 Use for household with aerosol style cans. This gauge does not have a shut-off. The T-handle is a piercing device only.