BCA Welded Steel AEG Gear Set (13:1 / 12:1)The new BCA Welded Steel Gear Set is an improvement upon traditional 13: 1 offerings in that the bevel gear and step gear are welded together, as opposed to being press fit like other brands. One of the most common failures from older 13: 1 gear set designs was the press fit components coming apart and spinning freely and independently inside the gearbox not what you would want for the sake of your ears and tech's sanity. Welded gears will ensure that