I have the LED kit by itself
here as well as the LED kit/Tailcap Switch combo.
I did a review of the
tailcap switch. These items aren't exactly bulletproof, but they work and they're inexpensive. I have both a tailcap switch and a
TerraLux Kit installed on the 2AA Mini Maglite I carry in my shoulder bag for work. (I also sell the
TerraLux Kits, which are brighter and more expensive than the RAM kits.)
Recently a customer bought one of the tailcap switch/LED combo kits from me, intending to use his 2AA Minimag mounted to a shotgun. He wrote to me to tell me he got a defective unit from the factory -- the RAM kit worked, but the LEDs were set crookedly in their housings, resulting in a beam that came out of the light at a slight angle. I had no such trouble with my own RAM kit (that's one of my personal lights in the review) but manufacturing variances like this probably happen fairly easily at such a low price point. QC remains the boondoggle of Chinese manufacturing, but it is getting better.
One other thing that deserves emphasis is the fact that the RAM LED kit is not focusable -- the beam comes out fixed. (The TerraLux kit, by contrast, can be focused from spot to flood after installation.)