Older sterling shower door . Have a screenshot with proper part with dimentions and part numbers circled . Part is unavailable from sterling/kohler .
A quick learner from illinois says:
January 18, 2019
Founda replacement ! 45 year old shower door part !
Dave Sr. from SWISCO responded:
January 22, 2019
Thanks for contacting us. Take a look at the 10-119 and 10-122 guides to see if you could use one of these. They're not exactly the same, but maybe you can adapt one of them to your shower door.