Shower valve identify and switched hot and cold

[sschoe2]

I have a shower valve in my house that I am unable to identify. The overflow plate says Gerber but I can find no identifying markings on the shower valve, I am not sure if it is Moen or what. It pulls out to turn on and right is hot and left is cold. I assume there is a shower cartridge that I need to rotate 180 degrees. If it is Moen I do I need a cartridge tool?

 

[GReynolds929]

Moen MoenTrol valve. Takes a 1225 cartridge. If it doesn't drip constantly you don't need to replace the cartridge. The lever handles turn opposite of the crystal handles. All you need to do is take the handle off and spin the stem 180°, then reattach the handle.