The Defender Dome is a 26ft. round unit with a step added for easy entrance and exit of the unit. Four people play at a time. The objective is to defend your goal while getting your 5 colored foam dodge balls in your competitors net. Fast action and great fun for ages 6 and up. This unit has 1 blower that requires a regular 110V household outlet to operate. If you do not have power available, Fun Source rents generators for an additional charge.