This is a first generation Lavatube. It is likely an original L-Rider Lavatube, but even if it isn't it's probably just as good.
There is absoultely nothing wrong with this unit. I've had one since the beginning of the year and it's worked fine.
There are 2 things you have to keep in mind with these. If you don't expect more than they are advertised as providing, you won't be among the whiners who gave this unit a lot of hate when they first came out.
First off, the current limit is 2.5 amps. This is so that noobs don't burn out LR coils trying to use a 1.5ohm carto at 5 Volts. If you try that it will automatically provide 3.7V, but the display will still read 5 Volts. 5V / 1.5ohm = 3.33 Amps. That exceeds 2.5 Amps. 3.7V / 1.5 ohms = 2.47 Amps. That is within the 2.5 amp limit.
So, the best thing to do is to use SR or approx. 3 ohm devices, exclusively. That will allow you to use the full range of available voltages without exceeding the 2.5A current limit. Do NOT use 3ohm Dual Coil anything. 3ohm Dual Coil cartos have two 3 ohm coils inside, but they are wired in parallel, so they present a total of 1.5 ohms to your APV. The Lavatube, and any other APV, will treat them like 1.5 ohm cartos. It will cut your voltage to 3.7V. That will effectively cut your wattage in half. Rule of thumb: Stick to about 3ohms. There's no need to buy low or high resistance anything.
Second thing to remember is despite the mfg's claims to the contrary, they do drop off in power as the battery depletes. It isn't radical until the battery gets pretty low. I generally do not run my battery below about 3.7V. This gives me an easy 10 hours or more and I don't really notice any power dropoff.
Other than that, it's a great device for that price. It's a giant step up from a Twist, or any disposable VV for that matter. It's tougher than it looks. It's aluminum with plastic covers on the aluminum top and bottom caps. I drop mine daily on wood floors and it hasn't broken yet.
Just get an extra battery, don't run it below 3.7V and stick with SR heads and you'll have no real complaints.