More power on tap with a dual battery configuration
Stainless steel clips fight off motor exhaust crud. Keyed safety with light and buzzer alarm sequence gives plenty of warning when the controller is "hot". But most valuable (if you are running longer wires to your overpowered cluster or mid-power/high power motors) is the option to slide a second 9V PP3 battery into the controller's pistol grip.
The 5m cable is sufficient for A-D motors but if you are venturing upwards in the thrust department with a cluster or Cesaroni composite propellant motors E-H, then you need to add another 5m of cable for safety's sake (and your insurance validity).
With a look and feel that would please Dirty Harry...Go ahead, punk, launch my day
Battery: one or two 9V PP3 batteries
Cable: 5 meters