The Pivotrim replacement trimmer head is a durable trimmer head with Pivoting technology to prevent line breakage. The head is made from carefully crafted glass-filled nylon for superior durability and abrasion resistance, it can withstand the extreme demand of any job. With its Pivoting line technology, the line bounces back when trimming against obstacles, instead of bending and breaking. So, trimming against hard surfaces such as chain-link fence, trees and concrete are no longer a problem. With strips that are already cut to size, you can load and reload line in seconds. All you have to do is feed the strips through the pivoting posts. That means cutting more with less downtime to get the job done faster, leaving you more time to do the things you want.