Both the clutch and the brake functions are contained in one single unit taking up a relatively small amount of space.
Simple control set up
Since the clutches run directly off the battery, all that is required is a switch. This allows the clutch to be placed into tight locations since wires can be easily routed to a simple switch on the control panel versus linkages that would be required with mechanical units.
Rather than an operator trying to fight against a mechanical linkage or a belt idler, a simple flip of a switch will engage the clutch, resulting in less operator fatigue.
PTO clutch/brakes help to meet industry stop times by assisting the blades to a stop.