I have own one of these for almost 8 year now . it be the best flashlight I ever purchase . I buy it when I be in college and work as a student Auxiliary for the college Police Department . my flashlight have suffer a great deal more then most flashlight can handle . it be be drop , run over , use as a hammer , use to pound in tent stake , constantly take on road trip , I can not even remember all of the thing I have do to it . all I can tell you be it still work . the best thing about the 6c be that it be lighter and thinner than the 6d but still be big enough and bright enough to get the job do . I even buy one for my best friend to keep in he truck .  to keep it work well you should occasionally apply a small mount of Vaseline to the thread to keep the thread and o-ring lubricate . if you do that it should last you a long time .