Tony, yes, they are hex shaped.
The bar comes as 3 pieces, a main long centre bar with 2 short end bars which fit inside the main bar.
Be careful when fitting not to let the short bars slide too far inside the main bar,slide them in almost fully and hold them with a turn or two of one of the locking bolts, just enough to stop them moving.
Offer the assembled bar up to one of the mover motor lever arms, slide onthen bring the other end up, slacken off the bolt to allow you to pull the short bar out to locate on the other mover motor.
Now, slacken the first locking bolt off and centralise the main bar, then tighten up all the lock bolts to the recommended torque figure.