I bought one of these from Swanghobby.com

I bought one of these from Swanghobby.com to start with to test it out on my trex 450. While I have to strap it under the landing gear like a big heli it fits perfect with no real weight gains to affect my flying. This has awesome punch and holds up under extreem 3D. Flight time under 3D loads is about 6 mins. (thats my safty time.) Sport flying is about 8 mins. I liked it so much I bought 2 more.