I am the owner of the 3-9 X 50mm Firefly. It is a great scope. As mentioned before just charge it prior to dark and the crosshairs will glow. I get about 45 minutes on mine but you can recharge it if needed. I have already taken 2 deer at dusk with it this year. No complaints. I plan to put one on the new rifle I just purchased. I will be going with the 40mm this time. For some reason the field of view at 100 yds is greater with the 40mm. For a great price on these and other scopes check out riflescopes.com I purchased my 50mm from them. Noone in my local area could even come close to matching the price that I paid for it.