A prop guard for the Hubsan Q4 (H111)/ Estes Proto X Nano/syncro/SLT 3-21-14 v2 fits all current quads. 6-16-14 v3 The lightest you could probably design a guard for a Proto. 8-12-14 v3.34 for enhanced 34mm props I'm a little disappointed with Estes qc and their motor pods being so loose. v2 was designed to fit later quads and also fits older ones with the smaller motor holder. The only other difference I can find is the serial number ending in 25 instead of 15. v3 even lighter and designed to minimize motor tweak. If you're still having issues I'd suggest gluing the pods onto the frame. The first generation of these micros had rock solid pods.