The Irwin? STRAIT-LINE? MACH6? Chalk reel features an easy fill and lock top that provides a wide opening for increased speed and visibility when filling the reel or accessing internals. The top locks securely with a 1/4 turn to prevent unwanted spills. The 100 ft hi-tensile line is 2.5X stronger than traditional chalk reels for fewer breaks on rough, abrasive surfaces and the reel has a 6:1 gear ratio to rewind the line 6X faster than traditional chalk reels.