I'm sure this has been covered but google searching, etc isn't giving the needed results.

I just bought a second hand 120 amp v3.1 esc. I want to get a program box for it. I'm seeing "2 in 1" and "3 in 1" boxes. Are these the same thing? Is there only one program box?

Thanks!

No there are two versions of the LCD box. The newer 3-in1 has the voltage checker pins on the side, and can accommodate the firmware for reading/writing to both v3 and v2 esc. You are best off to get the newer version