This Duoline trimmer line from Oregon combines two materials with different physical properties to create a super tough, durable trimmer line manufactured for professional grade applications. Highly durable & resistant to welding, this line features an abrasion resistant outer layer & breakage resistant inner core, allowing for extended use on even the longest, thickest grass. Suitable for use with most trimmers from various manufacturers, this trimmer line is a must have for the professional gardener.