It uses the Yihi SX130h chip, it lacks a few of the features found on the SX350j chip but completely understandable considering the price, the battery charge level indicator is a bar only, no actual voltage number like the 350j, it doesn't have the selectable power boost modes like the 350j, no readout for accumulated joules used and it doesn't have the 350's 5 position memory presets...the presets is really the only feature I miss, the others don't bother me. One other difference is resistance lock, on the 350j chip when you lock the resistance that's the number that's displayed whether the device is fired or static, on the 130h chip when the resistance is locked on a fresh room temperature build then fired it displays the active resistance and you'll see the number fluctuate during use as the resistance changes due to heat.
The body is all aluminum and it has a nice weight to it and the build quality is actually quite good, for a device at this price point I was pleasantly surprised at just how good it is overall, one of my concerns was the 510 connector and how solid it would be in terms of quality and its spring, no problem there at all and works as well as my SXM...at this early point I can't find any fault with this device and would highly recommend it to anyone looking for a very compact and pocketable mod, I don't think anyone that buys one will be disappointed...hope this helps.