This is a dreadful device, it has the worst throttle control I have ever used.
The throttle has a lock position at its center for when you want to be at zero throttle (not going forward or backward, which is great.
At any other position however, it has no friction whatsoever. This means that if you set the throttle to forward, around (for example) 75% and let it go, it just flops forward to 100% under it own weight.
I found it almost unusable and required me to remain tense at all times while using anything between 10% and 100% throttle because relaxing just meant the throttle just flopped about and I sped off and full steam ahead.
Further to this, one of the screws that make the thing join together would not do up and so it did not hold together as well as it should.
All round, pretty poor product. Be warned.