Ugly Twist by Shakespeare is a commercial grade bi-component trimmer line that outperforms other lines on the market. It delivers up to 15% longer runtime for cordless trimmers. The aerodynamic twist shape reduces line resistance and vibration, keeping the trimmer from slowing down, using less battery energy and cutting more. Scientifically engineered to deliver maximum durability and last longer than residential trimmer line. Impact modifiers are embedded within the nylon to keep your line from breaking away when trimming against obstacles such as brick, concrete, wood and steal. That means cutting more with fewer stops to get the job done faster.