This is a Photoflex Series 900 Speed Ring for all Elinchrom, Prolinca and Impact 100EX fixtures. It accepts any shaped Photoflex (or other brand) softbox.
OctoDome rotating connectors are made from heat resistant cast aluminum for durability, and allow rotation while mounted to your fixture with your choice of any shaped softbox. This ring is designed to fit Elinchrom, Prolinca, and Impact 100EX flash heads. Please note - for Elinchrom Quadra Ranger, the Elinchrom reflector adapter (B&H #ELEL26339 Mfr #EL26339) is required.