The number 1 customer complaint with any string trimmer is line replacement. EGO has taken this pain point away with the NEW EGO 15 in. Rapid Reload trimmer head. Compatible with EGO POWER+ String Trimmers: ST1500F and ST1500SF series only. The 15in EGO POWER+ String trimmer features the new Rapid-Reload system to quickly and easily load new cutting line.