Constructed from 1000D nylon 3M reflective strip One main compartment with inner mesh pockets (large and medium models are expandable) QuickClick (F25) seat mounting system with velcro seatpost strap Quick Release 6.3x3.1x2.9` (XS) 25 c.i. Black Small (1-100 c.i.)UPC/EAN/GTIN: 768661116521