I've used BC's for years... I like how they function, but have been frustrated with their lack of durability / reliability. After having them come apart on hunts, and at training classes (and always at the worst times), I started carrying a spare pair in my ruck. Then I finally got my first NF 3.5-10x50 F1 last year. The cover that comes with the NF works, but is slower (for me anyway) to get on and off for making quick shots. For example, if I'm hunting in the rain, I want my scope cover on while moving around. If I kick something up, the BC's function quickly enough to open them up and get off a quick shot at an animal. The cover that came with the NF - not so much. And I don't care to have the darn thing dangling off the side of the rifle when shooting at the range. I prefer the functionality of the BC type caps over the cover that comes from NF. So I will be putting in an order for the ADDMOUNT Flip Up caps, and am looking forward to finally having a flip up scope cover that is built to last.