So I just got this used Czar mfg. Userper 18650 tube mech mod off of ebay. I'm pretty disappointed with its performance however. I've got a 0.41 ohm a1 twisted kanthal build on my drop solo rda right now, and running a Samsung 25r. But whenever I hit the mod, its just super weak. I do notice that the button has a bit of side to side play in it, and if i just push up on a corner it hits better. The mod is very clean, doesn't appear to be warped in any spots, good threads, button looks solid and doesn't stick. So i'm not sure if it's a connection issue or just me expecting way more than I should have. If anyone has any suggestions or ideas as to whats going on I would really appreciate it. Thanks much, Hunter.