R-134a recharge hose with easy to use gauge helps prevent overcharging or under charging and unnecessary venting of R-134a.
Bullet piercing valves are used for round suction lines or uneven tubing. Can be installed on the high side as a permanent valve on the job.


High quality R134a refrigerant charge hose Charging hose is 19 inch in length for home use refrigerator ,A/C refrigerant systems. The end of R134a piercing can tap port can directly connect 1/2 ACME Male refrigerant piercing cans/containers. The end of R134a port fits R12, 22, 502 fittings.	Three scale readings The gauge has scale readings for R134, R12 & R22. Hose is made of heavy duty brass to last under extreme conditions, prevent leaking.	Upgraded BPV31 valve Compatible with: compatible with 1/4 inch, 5/16 inch, 3/8 inch outside diameter pipes. Made of corrosion-resistant metal BPV31 bullet piercing tap valve; Replace part #AP4502525, BPV31D, GPV14, GPV31, GPV38, GPV56, MPV31.

Take this as an example:

Notice: Always wear protective gloves and eyewear.
Turn the valve handle of the charging kit counterclockwise until the piercing stem is in the up position. This will prevent accidentally piercing the can. Screw the charging kit onto the can.
Attach the quick connect fitting to the low side service port.
Start engine and put A/C settings on maximum cool with the fan settings on high.
Turn the valve handle clockwise until the piercing stem has punctured the can.
Turn the valve counterclockwise until you feel the refrigerant leaving the can.
Suggest you to watch a guidance video before you do it yourself.