Just don't - Firefield Barrage 2.5-10x40 Rifle Scope

It's cheap, have not live fired it yet and honestly probably will not. The eye relief is non-existent, the overhang of the rear eye peice isn't enough to positively aim with a backup sight and it does not mount far enough back on an AR Rail for you to get a clear sight picture without having your nose touch the sight itself. The illumination is useless, daylight just turning it on completely obstructs your view from lense glare and there's no way to focus it properly...low light don't bother, it's blindingly bright on the lowest setting. It's a great airgun scope, and that's about it