I just received my Comp M4s with this lens cover. Absolutely the best cover for this sight. Install was was easy, and very secure, (5 sec. after a little heat to the rim). I also want to give a shout out to Vincent in packing for all the cool!! freebies included with shipment. If you have or want Comp M4 or Comp M4s IMO this cover is a must have. LaRue Rocks!!

Fits like a glove Just use a hair dryer like the other guy said. Love all the extra stuff LaRue gives you as well.

This is a great addition to your Aimpoint, I love mine...slightly heated it up with a blow dryer and it went on without a hitch.

I installed front and rear clear covers on my M4s in less than 3 min. Sorry to those who already did, but cutting your new covers is absolutely unnecessary. Instructions: 1) Replace battery, whether you think it needs it or not 2) Lift lens to the UP position as to avoid any possible heat damage to plastic lens cover. 3) Heat flange and surrounding area with hairdryer until surface is hot. 4) Slide unit on -- like butter -- and fine tune/center the hinge so cover looks and operates perfectly vertical. Have fun!

Good cover. View through the optic is slightly subdued with ARD vs. without, but still very good. Getting the caps onto the Aimpoint: Use a heat gun or a hair dryer on the part of the flip-up cap that slides over the scope and heat it up fairly good. (just don't overdo it and melt or burn anything, haha). It will soften it up significantly and you will be able to get it on without having to cut ridges off. I read this somewhere before I got mine, probably product reviews on Brownells, so I tried it and it worked great.

I received my Aimpoint CompM4s today along with this lens cover. I tried, without success, to put the cover on, but it wasn't happening. I got back on the Larue website and made sure I had ordered the right part. Once that was confirmed, I started reading the reviews and that's when I realized I wasn't the only one that had this problem. I followed their lead and cut out one of the ridges, which allowed the cover to slip right on. The cover is nice and snug now and functions great. I give this product 3 out of 5 because of the difficulty I had putting it on.

Re: Aimpoint Flip-up Front Cover w/ ARD killFLASH Filter Wed. 6/26/2013 8:05 AM CST: My review for this accessory is pretty much the same as what jgarvais wrote, except that I haven't cut off one of the inside ridges to get the thing on - yet; I hate to make irreversible changes to a new accessory just to get it to work as it should right out of the box. I'd give this cover a 2/5 rating for installation and a 5/5 rating for function. But, again, as jgarvais wrote, Aimpoint shuold really address this - ASAP.

I bought this accessory for the Aimpoint Comp M4s, and it is a love/hate relationship. First off, the inside of the cap has a slight ridge so that once it is on, the ridge will fit into the aimpoint groove and keep it secure (great in concept, poor in execution). This ridge makes it about impossible to slide on to the aimpoint, and the only way I could get it to fit was to cut one of the ridges flush with the casing, this allowed enough clearance for the cap to be twisted on the to Aimpoint. It will still a very tight fit, and I was pleased, until I had to change the battery of the Aimpoint, in which the cap won't allow you to take the batter compartment cap off while installed. I then had to remove the cap, and replace the battery, and then get it back on. While this doesn't seem like a big deal, just prepare yourself with 5-10 minutes of wrestling to get this cap on and off. Luckily you only have to replace the battery every 5-8 years, so not a huge deal. I give it 3/5 for installation due to the ridges and having to modify it to work on the M4s. As for the function of the cap, it is really nice, not only does the cap flip up/down, but the killflash does too. A very nice feature versus having to unscrew it all of the time. I give it 5/5 for function. Overall, I give it 4/5 stars. I would recommend it, however be prepared for a very frustrating install. Aimpoint should really address this.