*********Review update 11/13/14******** I originally purchased this item 07/21/12. The SL-20L was shipped with a new type of battery, NiMH (Nickle Metal Hydride). All of the stream light products I have used in the past 25+ years have been NiCd (Nickle Cadmium). So I took a chance on using the "Environmentally Friendly" NiMh battery. Since this new light also states it is a smart charging and only charges the battery as needed, I was very excited to buy it. Here we are 2 years later and I've purchased 2 new batteries since. After the first year of use, the NiMH would not hold full charge and the light auto-dimmed. If I wanted a dim flashlight I would have bought one, but I need bright. I purchased a factory Streamlight NiMH battery to replace it. A year latter, I've had to replace that battery. I was beginning to think the flashlight itself was not charging correctly and all StreamLights are lifetime warranted. After a little research, I've found the NiMH are NOT what they are said to be. I have purchased a NiCd (Nickle Cadmium) as a replacement. I give stream light 5 stars hands down on all of their lights (I have many others, SL20X, Stinger, Scorpion, Pro-Tac and 3 weapon mounted). I am a die-hard Streamlight fan. You can not beat their life time product warranty. The SL-20L is an awesome light, I still strongly agree it is a great product. But the NiMH battery is junk and tarnishes a great product's image. It is not suited for Public Saftey Use!!!! DO NOT BUY NiMH Batteies in any Streamlight product. You will be buying them more often that the old NiCd ones. Rechargeable batteries have a limited life to them, this is a given factor. Depending on your use, the NiMH will not meet the demands of Public Safety work. *********Original Post******** I have owned and used Streamlight products for over 25 years in public safety. I have an SL-20X still in-service for the same time frame. I've replaced the switch, battery and bulb, but overall it has been a major work horse that never failed me. Now enters a new generation of lights, LED C4. I have slowly changed to the smaller units on my duty belt and have been very pleased with their durability and brightness. When LED first hit the market, they weren't nearly as bright as the original incandescent lights. But the improvements with recent LED C4 have changed lighting completely for the better. From LED light bars on emergency vehicles to the actual handheld lights used in the field. So this brings me to making the change to the SL-20L. I use to carry two SL-20X, for the simple reason of the battery life. Most nights I would be fine with the single light, but some nights, scenes would require me to bring out the second light. I had the pleasure of seeing this new SL-20L light from a younger officer who had purchased it. I remember when Streamlight tried to make the combo light that had the 3 little LED with a regular incandescent bulb. I wasn't in the least bit impressed with that version. But seeing and using this new SL-20L, I was impressed. I purchased my own SL-20L and have been using the light for several weeks now. I charge it once a week at the beginning of my work week. The charge lasts all week during my shifts. It is very bright and appears to be just as durable as my old trusty SL-20X. I especially like that this light will charge in the original charging sleeve of the SL-20X so all of the SL-20 have one charger. I would recommend to anyone who needs the use of professional grade handheld lights to think very seriously about investing their money into this one. I remember paying over $100 25 years ago for the SL-20X, but it is still alive and strong and has been a valuable asset. I purchased this SL-20L with hopes it will serve me just as faithfully, and so far I have no complaints. Honestly, with the background and lifetime warranty Streamlight provides for all of their products, this is a win win deal. You won't go wrong with buying this light. I paid a little extra and purchased the one with new NiMH battery, which seems to be well worth the extra few dollars to allow me to use one charge all week long.