Aisan Model-C diaphragm repair kit for their regulators / vaporizers. These regulators are very popular in the newer Toyotas, Hysters, and Yales.

There are several versions of this regulator. They all have the same basic casting on the back plate:
692U
Model-C
W.P. 250 psi
W.C.O. 31 lbs

We highly recommend also purchasing the AISAN VALVE REPAIR KIT to go along with this item.  The valve material tends to get brittle over time.