This is the Topeak DynaWedge Small Saddle bag. Aerodynamic water-repellent lightweight saddle bag with a unique center opening for easy access to tool, tube and other essentials. Fits neatly under saddle with adhesive straps. Specifications: Capacity: 0.8 L / 49 ci Material: Elastic Polyurethane Fiber/ EVA Foam Bag Attachment: Adhesive Straps at Rails/ Rubber Strap at Post Seatpost Diameter: Fits 25.4 - 31.8 mm Size (L x W x H): 18.5 x 6 x 14.5 7.3" x 2.4" x 5.7" Weight: 98 g / 3.45 oz