When the owner of the Dial-H, Robby Reed need to be in two different sites, he dialed S-P-L-I-T on his dial. However both sides where morally opposed. The Wizard is the heroic counterpart and arch-enemy of the Master. He created the H-dials for Chris King and Vicki Grant to fight the Master, his monsters and other villains.
Eventually, both sides became one again.