Acceleration trigger

An acceleration trigger, informally known as a rev trigger, is a type of trigger used for certain flywheel dart, disc and high-impact round blasters.

Details
An acceleration trigger acts as a "power switch" for the blaster and is located directly under the firing trigger. Pulling the acceleration trigger causes power from the battery pack to be sent to the flywheel system, powering the flywheels and making them spin. When the trigger is released, the flywheels will stop spinning. Blasters with flywheel systems cannot be fired unless this trigger is held down.

History
The 2000 Power Nerf Ballzooka MP150 was the first blaster to use an acceleration trigger, although it was located on the foregrip of the blaster unlike modern blasters, which have it under the firing trigger.

The concept of the acceleration trigger was revived with the release of the Vortex Nitron in 2011. As flywheel blasters began gaining popularity, it became more common for blasters to feature acceleration triggers.

Trivia

 * The acceleration trigger featured on the Nitron is larger than the one featured on most other blasters.
 * Some blasters such as the Firestrike, Star Shot, and Lumanate feature a similar trigger that does not perform the same task. In the cases of the these blasters, the trigger instead activates a built-in light and not flywheels.
 * The Dart Zone BallistixOps Apex has a grip safety that looks similar to an acceleration trigger.
 * The acceleration trigger is considered the priming mechanism equivalent of flywheel blasters.