Wind Defense

Wind Defense (妨害気流 (ウィンドディフェンス) ) is an anti-sniping defense equipment used to protect VIPs in Academy City.

Background
They are machines which resemble gigantic electric fans and can be equipped on special crane-like vehicles. The equipment deliberately creates gusts around the designated VIP, throwing off the trajectories. This is done as sniping can be easily effected by the wind. Usually four of them are used to create wind swirls that surround the VIP's assembly area. The third generation versions use random numbers to generate random air currents.

Battle Royale Arc
During Sunazara Chimitsu's attempted assassination of Oyafune Monaka there were several Wind Defense installed around the assembly area. However, Chimitsu managed to silently disable all of them using his MSR-001.