Hello
I have a customer who was purchasing a home and the previous owners removed the valve retaining ring and shower valve. The temperature balancing cartridge was left in place and now I am looking for a replacement. I first thought it was Delta because of the spring and rubber seat. but the valve retaining ring is smaller than a DELTA, one piece cartridge. I spoke to another plumber and he thought American Standard, but the replacement balancing cartridges I could find have a different inlet configuration (red seal).

Any thoughts would be greatly appreciated
thanks
Name:  posi temp cart 2.jpg
Views: 69
Size:  81.4 KBName:  shower valve 2.jpg
Views: 63
Size:  53.8 KBName:  shower valve cart 1.jpg
Views: 59
Size:  90.9 KB