The new Lastolite sync block (non TTL) is ideal for photographers who want the benefits of using a radio trigger but do not have a sync connection socket on their flashgun.Simply attach the cast aluminum sync block to the bottom of the flashgun and then plug the sync cable attached to the block into the remote radio trigger receiver unit.The flashgun can now be fired via the remote transmitter fitted to the hotshoe on the top of the camera.The Lastolite sync block is compatible with any radio trigger featuring a PC sync/X sync socket.