Keep your belongings safe & dry with the completely waterproof Monsoon Bag. The roll top, elastic closure mechanism & quick release saddle rail bracket make the Monsoon Bag easy to install & built to endure the elements. Features: - Waterproof Construction - Roll Top Closure System - Quick Release Saddle Rail Mount - Reflective Logo Highlights - Material: 210D Ripstop Specs: - Size: 5.5? x 2.5" x 3.5"/ 48 Cubic Inches (Medium), 6.5" x 2.5" x 4.5"/ 73 Cubic Inches (Large)