polyester [Opening hook and loop]:These plate carrier shoulder pads also fit very snugly.Opening hook and loop design,easy to add or remove,makes it fit most 2' (Maximum 2.5') in width shoulder straps for FCS,LBT,JPC and ect vests or sling bags,backpack,car seat belts,messenger bags.Hook inside of the pad creates friction so the pad doesn't move freely up and down the strap [Lightweight and breathable]:These vest shoulder pads are made of 900D polyester,pu coated materials,waterproof,breathable and heat dissipation.The backpack shoulder strap pads have a honeycomb design helps manage heavyweight as the weight gets evenly distributed throughout.This feature also helps the shoulder pad shock absorbing [Dimensions and weight]: These backpack strap pads measures 8.5' L by 2.5'W by 0.7'H,0.137lbs [with three loops]:These comfort soft cushion sling pads for plate carrier vest comes with 3 Molle type of accessory attachment spots which are about 1" apart. The center one is elastic while the end ones are of nylon weave where you can attach items that you need which you need easily accessed [ Free Trial]: We are confident to make you satisfied with our shoulder pads as we provide the best quality products and superior after-sales service. If you are unsatisfied with them, you can rest assured that we will deal with it to your satisfaction