Commercial grade heavy-duty square 105 weed eater string. Diameter: .105 inches (about 2.6-2.7 MM). Shape: Square trimmer line Weight: 5 Pounds, approximately 1038 feet in length. Material: Commercial grade high-quality nylon, and high hardness inner core. Replacement: Oregon 22-805, 22-905. Fits: echo, husqvarna, Redmax, Ryobi, Black & Decker, Cub Cadet, Weed Eater, Weed wacker and more trimmer. Notes on the installation of trimmer line: Choose the appropriate length of the weed eater string. In general, the exposed length of 10-15 cm is more suitable. If the trimmer line is too long, it will be easy to break; it's too short will reduce work efficiency. Make sure both sides are the same length. Otherwise, the mower will shake because of the imbalance. Precautions of use: Before using the mower, remove hard objects such as stones from the lawn. Do not use the mower on wet grass. For example, the lawn has just rained or watered. When the ground is wet, your control of the mower may not be stable.