I have searched the forums and other than one mention by a vendor there does not seem to be much discussion about these units. After trying the T3s and liking them I was getting more and more disappointed in having the burn out pretty quickly. All the Kangers are 510 Ego type APVS. The New T5s have a rebuildable kit that you can buy and replacement is very easy. Do search on Kanger T5 here to see some pics and more details. I highly recommend them. This after several weeks of use.