Motor retaining screws help you securely fasten the motor to the chassis. This prevents the motor's torque from twisting the motor which can adversely affect the gear mesh and/or twist the chassis which affects the car's handling. Note that not all motors/chassis are designed for motor retaining screws. The motor's housing ("can") must be drilled/tapped to accept M2 screws and the car's chassis (or motor pod) must have pre-drilled holes which line up with the motor holes. Screws have philips panhead.
Package of 10.