World models uses two different covering materials. The Sky Raider series uses the lighter material which is not very durable. The LA Racer is a low wing second plane, but has the heavier covering material. I have a LA Racer with an old OS plain bearing .40 that provides adaquate power. I saw the Nitro Models Low Wing Trainer and it looks good, but the poor reputation for customer service made me choose the World LA Racer instead.