I used to fly with the guys that made them for Kangke (While I was in China) - I used to fly the 40 size over there.

My son and I refered to them as the "unbreakable plane" - a great flyer and a lot of fun. Otherwise nothing in particular needed with them.

Just beware of the nosewheel plastic mount - they can be a little fragile. I converted mine to taildragger.

For $40 - well worth it.