The IRWIN STRAIT-LINE MACH6™ Chalk Reel features an Easy Fill & 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 ¼ turn to prevent unwanted spills. The 100' 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.