this is a great looking product on any M4, the batteries required are a pain to get hold of in any store ( I would recommend buying then off of Zero One) but when I put the batteries in the light I was really impressed at how bright the torch was it gives you a great beam to aim down and the light has a very good range on it.
the reason this is 4 grenades and not 5 is because the navigation lights don\'t work (the little ones above the main light) an even though I wouldn\'t use them much it would be a nice feature to have. also don not shine this is the mirror or in your face because after wards you cant see s**t. the only other bad thing about this is that the left pressure pad doesn\'t work to activate the torch, so if you are left handed I would recommend buying this. apart from those small issues this torch is a great buy and well worth the £60 you will be spending, great customer service form Zero one as per usual and I received from FedEx the next day.
P.S you get a MOAM with it as well which was awesome !!!!