This Elinchrom Multifunction Cap for Ranger Quadra not only protects your Ranger RQ S or A flash head, flash tube and modeling light plus the 5.3" (13.5 cm) RQ reflector it fits on to--it's also a frost diffusion filter for the flash, and it accepts color gels. A lot of bang for very few bucks.
For Ranger RQ S or A flash heads