I have two Vamos, one that currently isn't working. I actually have bought three....roller coaster took care of the first one. On a lark I purchased an Itaste SVD....looks like a Vamo...same size....I don't know if the V4 or 5 lock the V/Watt settings, but this SVD does. I have been vaping it for a couple months and it looks new. Loved my Vamo....but it's an old girlfriend now...SVD is better built with more features...it's a Vamo in disguise.