I use R416a in place of R12, it will also work in place of 134a and has a lower head pressure than R12, it's also a drop in replacement in both stationary and mobile R12 applications. I recently put 24lbs of it in a walk-in cooler designed for R12 at a restaurant. When converting an R12 system to 134a, the oil in the system must be changed or supplemented with a synthetic additive to get oil return. An oil change isn't needed with R416a. ^_^
TDD