Question: Does Tektronix offer Gel Timers?
Answer: Yes, Tektronix did sell the 22A Gel Timer Meter. The 22A Sunshine Gel Timer Meter was only sold through Cole-Parmer.
This specific model has been discontinued. Cole-Parmer has a suggested replacement, WU-98930-42, that you can see if it will met your needs.
Sunshine Gel Time Meter