Fatmax, 100' Chalk Line, Precision 3:1 Gear Drive System For Fast Rewind, Spare Hook Included, Improved String Has 2X The Tensile Strength & Lasts Twice As Long In The Field, Ergonomic Rubber Grip Case Design That Is Water Resistant, Holds Up To A Full 4 OZ Bottle Of Chalk, Special String Locking Mechanism, Replaces Model #47-120.