Product Description Specification Compatible: M4 / M16 Construction: Polymer Capacity: 30-Round Real-Cap & 130-Round Mid-Cap Mode Switchable Overall Length: 180 mm Overall Width: 65 mm Overall Height: 25 mm Weight: 159 g Enhanced Construction: One-Piece Reinforced Magazine Shell Modular Internal:Easy Disassembly for Cleaning & Maintenance Modular Shell: Quick Replacement for Optional Shells Various Capacity Switchable Mid / Real-Capacity Or High-Capacity Lengthened Follower: Snag-Free & Reduce BB Waste Impact-Absorbing Design: For Outstanding Reliability Reinforced Material: For Long-Lasting Durability WARNING: Cancer and Reproductive Harm – www.P65Warnings.ca.gov/product Customer Reviews