Quad Darts (BTD5)

"Shoots 4 darts per volley instead of 2."

- Official Bloons TD 5 Mobile description

Quad Darts is the first upgrade on the first path for the Heli Pilot. In BTD5 Mobile, it costs on $510 on Easy, $600 on Medium, $650 on Hard and $720 on Impoppable. It allows the Heli Pilot to shoot 4 darts every volley instead of 2 darts per volley.

Summary
Generally, Quad Darts is used as an early-game upgrade when using the Base Heli Pilot. Similarly to the lower tier, the Base Heli Pilot finds most use on long tracks and maps where the infinite range is appreciated.