The manual for the EGO ST1500F Rapid Reload Bump Head string trimmer recommends Model Number AL0951 twist cutting line, implying that's an EGO part number. But this particular cutting line or any EGO-branded line does not seem to be available anywhere including Home Depot or the EGO web site. Also, the cutting line that was on the trimmer when I bought it is not twisted. It's just round in cross-section. Home Depot sells several different brands of cutting line for string trimmers, but none of them are EGO brand and none of them are twisted. Why is twist line recommended, and if it's all that important, where is one supposed to buy it? So since this part number appears to be non-existent or unavailable, what type of cutting line does EGO recommend for its trimmers?