BPV-31 Bullet Piercing Valve: Replacement Part Number : AP4502525, BPV31D, GPV14, GPV31, GPV38, GPV56, MPV31; Compatible: Compatible with 1/4", 5/16", 3/8" OD tubing Universal Retrofit Valve: Retrofit valve converts from R-12 to R-134a air conditioning system, fits side ports down to 7/16"; for pre-1994 vehicles, includes R-134a replacement EASY TO USE: BPV-31 Bullet Piercing Valve: Just screw on, then put; BPV-31 Bullet Piercing Valve: You only need 1 hex key (included) to install this part; its compact design requires only 5.08 cm of clearance area for installation and use DURABLE MATERIALS: Both kits are made of corrosion-resistant metal that won't wear out or rust over time, leak-resistant design, safer for you Features: Universal Refurbished Valve: Application: For 0.95 cm low side ports. Fits all cars older than 1994. Compatible with R-134a replacement fittings. Function: Converted from R-12 to R-134A air conditioning system. This valve can be screwed to the top of a closed AC system with just a little fridge or removed from the top. BPV-31 Bullet Piercing Valve: Replacement Part Numbers: AP4502525, BPV31D, GPV14, GPV31, GPV38, GPV56, MPV31. Compatible with 1/4", 5/16", 3/8" OD tubing. Easy to install: Clean copper pipes with a wire brush or abrasive cloth. Then pin it in the smoothest part of the copper pipe to ensure a tight seal.