I have been using These Transparent Red 2xAA Battery Box with On/Off Switch battery boxes for about 6 months and they keep breaking. One drop to the floor and I have no more mod. I am trying to find a box that is durable and lasts a long time. I wouldn't mind a box for a 18650. All my flashlight mods work but then stop working after a month. I have no clue why. I would also purchase a mod for the 18650 but it needs to be durable and last a long time. I am in love with 510 LR attys and would like to stick to that. If anyone could help it would be appreciated.