silent, as I said earlier I have two. I use them for 3D, and will hunt this year with them. I shoot in the evening until I can't see the target well enough to tell where I'm aiming sometimes, but the pin is glowing bright. I put a different sight on for 3D hunter class. This morning I was in the shadows and my target was in the sunlight, I couldn't see the pin to make a good shot. I went in & got my Pat with the Cosmic, and the pin was very easy to see. I could easily make a good shot. I'm going to put the Cosmic back on & shoot for fun. The scope is clear, so I don't really notice it. I don't mind the two thumb screws as I expect I'll set it at 25 yds and forget it, for hunting. I'd think if there was time to adjust, two screws won't matter. I chose these for the extremely bright pin. They're also very light and compact. I use a pencil to mark yardages. The marks can be erased if need be. When I walked in the shop I could see the Cosmic pin glowing. None of the other sight's pins were visible. Yes, the sight is the best one out there, in low light, IMO. I'm perfectly happy with mine.

Phil.