I got tired of waiting for Super-T to release the Shockwave, and for Cisco to release the Helix, so I built 26650 box mod. Nothing advanced or fancy here, just a very simple box mod. I used a 2 C cell battery box, connector, and switch from madvapes and the 26650 battery from AvidVaper. I gutted most of internals of the battery box and had to grind the inside of the cover and under the battery in order to get it to fit. Battery fits nicely in my Pila and Shekor chargers. Just completed it this evening so I have no idea how long the battery will last.