The Photoflex Series 900 Speed Ring for SP Systems Excalibur, SP90, 120, 920, 147 allows mounting of a Photoflex or any other brand of rectangular or octagonal softbox to the front of these flash heads. It adjusts with its 4 screws to mount to the front of flash heads of up to 4.75" in diameter.
OctoDome connectors are made from heat resistant cast aluminum for durability. They allow full rotation of any shaped softbox while it is mounted to your flash head.