MVP Proton Reactor OTB OpenMVP Proton Reactor OTB Open The MVP Proton Reactor is a stable to straight, highly durable midrange disc from MVP Disc Sports known for its reliable, controlled flight and high visibility, transparent plastic. Featuring Gyro technology, it serves as a workhorse, offering a dependable 5 5 0. 5 1. 5 flight rating suitable for both backhand and forehand shots. It is often favored for its, stiff, grippy feel and ability to hold lines in windy conditions