Eagnas Challenger 1 Racket Stringing Machine - Free String and Stringing Tools Six-point, suspension mounting system Drop-weight (gravity) tensioning system Free string and stringing tools Linear ball bearing string gripper with with unidirectional clutch (locking ratchet system) Two slim diamond-coated, heavy-duty dual-action thumb-adjustable stainless steel swivel clamp (fixed clamps): 2 PN-1012 tennis clamps