Holman Swing-Out Single Spool Holder Model 40233Holman Swing Out Single Spool Holder Model 40233 The Swing Out Spool Holder mounts to the end panel of shelves and can be rotated to stow the holder against the shelf, or to deploy it into the aisleway of the vehicle. This allows a user to deploy the spool holder, load a spool onto the holder, spool out a length of wire, unload the spool, and then stow the holder back out of the way. This can free up precious floor space and maintain safe aisle