Well, I returned my Eagletac T20, because it was not the new U2 emitter and had several nicks in the HA coating. Today I get the new one and now the advance modes is messed up. It would work twisting back and forth but eventually will stop working. Literally it would not turn on unless I twist it back tight. This really starting to **** me off with the QA of Eagletac. I love their lights but damn water condensation on the D25, now this! At least my G25 has no issues. Then I have 6 Orbtronic 18650 that won't work in the T20. They won't work correctly, due to the length. T20 recommends up to 68.5mm and the Orbtronics are 68.7mm. That .2mm reall going to make the difference? It works ok on my G25. Well this time I'm not going to pay to ship it back. This is a defective product straight. I paid to ship it back last time this I'm not. I shouldn't have paid the first time. Has anyone with the T20 have issues with battery size? What about the twisting head modes?