Kissler & Co.
Hot Water Cartridge Ceramic PricePfister
You will find that ceramic doesn't fade or discolor under sunlight exposure.
Kissler & Co. 55-0003 Symmons SC-3 Generic Renewable seat
The F3SN-A0307P25-D-04 F3SN-A0307P25-L-04 model is a common replacement for older safety light curtains.