Check Lippert Manufacturing...most likely your door/screen door was made by them.
Scroll thru their on line catalog for screen door replacement parts...they list several including a clear like you have pictured, their SKU #234101.
Also, just google "RV Screen Door Slider" and dozens of sites/pictures pop up.
US Navy Vet
Retired Law Enforcement
2021 Ford Ranger Lariat
2022 Jayco Jay Feather 24RL