For use with the EGO POWERLOAD™ 40cm Line Trimmer with Line IQ (ST1620E-T). The number 1 customer complaint with any line trimmer is line replacement. EGO has taken this pain point away with the World’s First EGO POWERLOAD™ trimmer head. Rewind your line faster, simply insert the line into the head and press the POWERLOAD™ button. World's first auto-sensing technology monitors and feeds the line for a continuous 40cm cutting swath. The 40cm cutting swath, bump-head line advancement, and professional-grade 2.4mm cutting line make this tool truly professional grade. EGO parts are designed specifically for your EGO POWER+ products and offer the highest quality, performance, and value.