The recoil spring on my Umarex Glock 17 Gen 4 was damaged and although repaired was never quite as good as new. I was struggling to find anywhere with a genuine part in stock and didn't want an aftermarket part as they're always hit and miss as to how good they are and most are increased recoil which I am not interested in. This is a genuine VFC part, very reasonably priced and was shipped promptly, excellent service!