I bought this for my Ruger 10/22 Takedown. It fits perfectly while still allowing the barrel to be attached and detached, and the scope can remain on the gun and still fit into the Takedown nylon case very well. I would have given this product 5 stars, but the reticle (crosshairs) were misaligned (turned clockwise). So, I sent it back and ordered a second one. The reticle in the second one is still a hair off, but acceptable (for the price). If you are an Amazon Prime member, you might want to order two of these scopes at the same time, keep the best one, and send the other back (prime members get free return shipping on prime products). This is a great scope for the 10/22 Takedown, and I'm pleased with it now that I have one with a semi-straight reticle. You'll be pleased with it.