Shield Arms made the following improvements with their Gen 3 Magazine:

Modular tooling, allowing us to make the S15 and S10 magazines simultaneously
Raised ribs on the back of the magazine allows us to fully match the OEM magazine position in the mag well, which should eliminate any tolerance stacking that results from Glock frame variations
New steel, new coating, new heat treat process - The new steel is slightly thicker, tougher, and now comes with a new standard black nitrocarburized QPQ finish for a high degree of corrosion resistance.

Mag Catch Requirement: It is required to swap out your plastic OEM mag catch with either the standard steel mag catch or the premium steel mag catch. Here's why. If you don't swap your mag catch you may have reliability issues. If you use another manufacturer's mag catch you may have reliability issues. S15 magazines were designed to work with Shield Arms steel mag catches.

STANDARD FEATURES
15 round capacity - Increased Capacity, Same Reliability
Same length as an OEM Glock 43X/48 magazine
Easy to remove, impact resistant base pad
High lubricity finish options
Made in the USA, Patent-pending

Product Code: SA-S15-N-GEN3

For more information visit: https://www.brownells.com/gun-parts/magazines/handgun-magazines-parts/s15-9mm-luger-magazine-for-glock-43x48-gen3/?sku=430105954

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