I have that holster, I got mine from Midway, they had it cheapest when I was shopping around.
It is a perfectly good range holster, but it is about as suitable for concealment as a .22 pistol. It locks onto the receiver and frame in a way that should fit any Ruger mk___ in either frame style, and will even allow some optics with the top slot. Retention is pretty good, trigger is well protected, longer barrel muzzles will protrude a bit.