The GPM MKV6041S input shaft cup is manufactured from 4140 carbon steel to deliver a durable replacement for ARRMA KRATON 6S EXB drivetrains. The component is designed to maintain positive engagement if the attachment screw loosens, and the Safe-D configuration integrates the input gear with the drive cup to ensure steady torque transfer under load. Suitable for hobbyists seeking a serviceable, long lasting drivetrain part.