This bungee-action shoulder strap absorbs the weight & the down force that a standard trimmer strap cannot, making your yard work a breeze without breaking your back. It feels like you are in Zero Gravity! With its contoured cushioned design, our deluxe shoulder pad promotes stability and a backward migration of the trimmer which promotes better postural alignment. No bending, No straining!! By making the trimmer feel lighter, you no longer "Clench Up" which means your arms can now easily control the trimmer with more accuracy and precision.