You hear the thundering sound of blades approaching from behind, but you do not see your pursuer yet. As the sounds get louder, you realize your husband is having fun with his Align Trex 250 again: inside the house. Thankfully, this is one of those remote control helicopters that is small enough to use indoors, but not so small that it cannot be used outdoors as well. The best thing is that there are plenty of used Trex 250 helicopters available if you are not ready to make the investment in a brand new one. This is especially great news for novice remote-control aircraft controllers, since there can often be a learning curve. Of course, that is when Trex 250 parts come in handy, too. With the huge selection on eBay, you can find just the Align Trex 250 you want, whether it is used or new, and you can keep it flying without having to spend a fortune.