Husqvarna RA850 Reciprocator Attachment - True reciprocating action, safer than trimmer line & bladeCombi attachment for Husqvarna combi trimmer models 129LK, 524LK and 525RJD. Designed for safer and more efficient weed control and grass edging along footpaths and on gravel paths, where an ordinary trimmer would cause the risk of throwing rocks and debris. The robust, durable reciprocating blades work back and forth to cut the weed like a scissor, similar to a hedge trimmer.