Compatible Model: It can be fitted to all brands of sthil, Husquarna, Stiga and many other brands. Not suitable for electric trimmers Load & Go Simple charging system – Tap & Go Cord flow system: Interchangeable reinforced aluminum eyelets - Reinforced steel button - Reinforced plastic structure - Head with D.130 - M10 x 1.25 - Inner insert - Maximum d. 4 mm round - 1 refill of 7 m of d. 3 mm round wire Wear-resistant: Button with interchangeable steel reinforcement - 2.4 to 4 mm round wire or 3.5 mm square Instructions: Align the eyelets. Pass the thread into the head through one eyelet and let it out the opposite side until you have two edges of the same length. Turn the molded knob counterclockwise. The head is ready to use.