G48 mos easy install. - Shield Sights Reflex Mini Red Dot Sight

Purchased the RMSc 4 MOA with glass for my G48 mos. Easy install, came with all the mounting parts needed. I found the 4 plastic washers needed to mount to the G48 questionable material vs. metal, but were necessary due to the screw length (main reason I gave it 4 out of 5 stars). Also, there were no instructions regarding the plastic washers. Two washers are need for each mounting screw. I figured out they were needed by trial and error. I hope they hold up over time as there were not any extras. The model I purchased does have a side load battery drawer so I'm hoping that mitigates any wear and tear on the plastic washers as I won't need to remove the sight to change the battery. Appears to be able to be co-witnessed with the iron night sights (I replaced the standard Glock sights). ​Giving it a try at the range tomorrow.