A pair of these Vibration Reducers for Trimmers mounted on one's string trimmer, brush cutter, or other shaft-driven yard tool can reportedly cut extended-use felt vibration up to 50%, along with the resulting discomfort/fatigue. Made of NAVCOM (Noise and Vibration Control Material), the round, fluted-shaped reducers are slipped onto the shaft (one toward the top, one toward the bottom) and secured via the provided zip ties.