An affordable alternative to factory Glock® magazines, the ProMag® .40 S&W 13-Round Magazine for Glock 23 pistols features a durable, high-impact DuPont™ Zytel® polymer body with a full-length steel lining for lasting performance. Numbered witness holes offer quick, visual round counts, while precise tolerances deliver a snug, precise fit for added reliability. Plus, the strong steel spring, coupled with a non-tilt polymer follower, ensures reliable feeding and quicker loading.