ZMR 250 motor guards / protectors

I fly my ZMR like I stole it, this means i'm not afraid to crash it, that said I crash quite a bit trying to see what I can squeeze the quad through =). At first I made these with a 10 degree angle to increase forward speed but found that they protected the the motors so well that we now put them on all our quads! Pictures show 2204 sized motors and they have been in many many crashes and are still in perfect condition. (motors in picture were flown for a while without these but have sustained n