Ade Advanced OpticsRD3-009 Crusader Red Dot Sight – Reflex Optic for Ruger Mark I II III IV IV-Lite with Mounting Plate – Doctor Footprint – Compact Red Dot for Handgun, Pistol or Picatinny Rail Use

Bought for mounting on my Ruger Target Mark IV pistol. Overall mount and optics are great. Went this way so not to have a Picatinny rail running along the gun barrel. Also the Optics mount right to the provided mount minus the piece for mounting on a Picatinny rail. This keeps the mount lower to the barrel. On the barrel rear mounting hole to attach the mount to the hole is a through tapped hole. The screw provided for mounting is to long and will protrude into the barrel and contact the spring on the slide. You will have to grind down the provided screw to to be flush or undercut of the inside of the barrel. Other option would be to get a smaller length screw. Grinding the screw to length was an easy task and assembled with no problems. Works and looks great on the pistol.

I had no problems installing this on my MK II 22/45. But, I do have difficulty getting it to come on and with adjusting the brightness. I've quit turning it off, and I now rely on the shake awake feature solely to turn the dot on and off.Everything mounted up solid and I recommend this setup to value shoppers. I'm sure you can get units with more bells and whistles, but this unit is a good value and has been a solid performer for the short time I've had it.

Fits perfect and comes with everything you need to install. Only thing is you need the tool to get the sight screws for your own pistol before you put there screws in then go from there.

The screws supplied with the sight are too long, it will be necessary to shorten the rear screw. The rest of the assembly process is cumbersome at best. The sight has to be unmounted to change the battery, which means resetting. UPDATE: Emailed their tech support team. Instead of knowing what screws should be with the model specific mount, they asked me what length screws I needed. So I broke out the calipers and bench grinder and ground the supplied screws down to exactly the length needed. If you make a product support call, expect Larry, Mo, or Curly to be on the other end. “Oh, we can get you screwed right up, nyah nyah nyah…”

I was tempted by the price don’t make the same mistake. Battery access is underneath you will end up taking the red dot on and off while trying to get the silly thing to power on. Not to mention the threaded battery cover has about 1 1/2 of super fine threads that make it a real chore to get started each time. Used mine 3 separate occasions on a Ruger mark 4 22/45 each time I had trouble with the red dot shutting off mid shoot. Went through a 6 pack of little batteries trying to trouble shoot it. Emailed company and received little help besides “tighten the cover” or “try different batteries”. To far past to return once it was all said and done. Ended up getting a vortex venom well worth the money- should have just bought it in the first place!

I like the build quality. Assembly kit was complete and well made. Just by luck this set up was dead on and no adjustment was needed. I'm using this on a Ruger 22/45 Mark III. It's not the best looking set up but this product gets me on target fast.

How much sight can you buy for $80 bucks.Wow I’m impressed. I’ve used red dot sights for years but never this type as mine were always scope type. After about 500 Rds the sight keeps its zero, has quick target acquisition and the dot is easy to see in sunlight.

PROSit's under $100. Held up on zero on my 5.56 and 9mm with in 100rdsCONSThe screws for the mark iv lite mount were too long. Had to grind them to fit. The company knows about it, it's in the manual and couldn't do anything about it.The mount itself is not flush. It's protruding on both ends of the optics.The shake awake does not work.Battery is on the bottom of the optics and requires dismounting to change battery.