Durable and Impact Resistant Glass Fiber Reinforced Matte Black Polymer Construction. 33 Round Capacity with Durable Co-molded Polymer Window and Debossed Round Count Indicators at 33, 25, 20, 15, and 10. Anti-tilt High Visibility Blue Follower and High Longevity Stainless Steel Spring for Reliable Feeding. Flared Lower Main Body with Raised Bosses for Additional Grip Retention. Compatible with GLOCK 17, 18, 19, 19x, 26, 34, and 45 and Most Other Pistol Caliber Carbines, Large Platform Pistols, and Pistol Clones that Take GLOCK Magazines. Compatible with Reversible Magazine Release for Left or Right Handed Users. Easy to Remove TPU Over-molded Anti-slip Base Pad