pcucit Yes, 2.1 x 5.5mm. Not sure why the product title says 5.5*2.5, that seems incorrect to me!

pcucit Diameter is 6.75in, or 17cm. Not sure what the pitch is - it doesn't say.

pcucit It can do 30-32 kph (19-20 mph) on the stock battery. It can also do 45 kph (28 mph) on a 3S battery, although one that'll fit into the smallish battery compartment might be tricky to find. You could always just strap it to the chassis underneath the body if it doesn't fit in the battery compartment...

pcucit Yes, you can use many of these at the same time. You can switch the frequency of the on-board camera (and on the goggles to match the camera) amongst approximately 40 frequencies (although in practise you can only use about 10 to 15 different frequencies at the same time, due to cross-talk between frequencies that are close together). The controller is 2.4GHz, this doesn't need to be switched, since many of these (more than 400) will work independently, simultaneously.

pcucit Sì, è pronto a volare. Può decollare solo da terra molto liscia, poiché le ruote sono molto piccole.

pcucit Mode 1 = right-hand throttle. Mode 2 = left-hand throttle (most common in Europe and US)

pcucit No, I don't believe so. You wouldn't want to anyway - this plane is just too small to fly stably without the gyro. It flies great with it though!

pcucit Nope - 25-30kph max out the box. You might get 35kph with a LiPo (the included battery is a Li-Ion). They need to stop this false advertising of speeds!