Open Box Return-Sylvan Arms AR-15 to 9mm Conversion Block for Glock Pattern Magazines – GCB100

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Easily Convert Your AR-15 Lower to Accept Glock Magazines

The Sylvan Arms AR-15 to 9mm Glock Conversion Block – GCB100 is a drop-in addition that converts your AR-15 lower to a 9mm Lower for use with Glock magazines. This accessory is designed to install in Mil-Spec lowers almost exactly like a standard rifle magazine, without resorting to buying a separate lower receiver exclusively for Glock mags.

This fantastic conversion kit from Sylvan Arms is one of the best accessories on the market today and increases the modularity of your AR-15 pattern rifle.

Takes Your AR Build to the Next Level

The Sylvan Arms AR-15 to 9mm Glock Compatible Conversion Block is designed to fit into the magazine well of your standard AR-15 and reduces all the extra space and allows Glock 17 and 19 pattern magazines to fit. The fit and function of this adaptor are exceptional and genuinely ingenious which makes it one of the best AR-15 accessories on the market today.

It is machined from black oxide steel and 6061-T6 aluminum coated with a black anodized finish for extreme durability and wear resistance. This adapter promotes easy installation and swap-out when needed and takes your AR build a step further to switch that big 5.56mm-sized hole into a 9mm-sized one to fire your favorite 9mm ammo.


  • Easy to install and swap out
  • Accepts popular Glock 9mm magazines
  • Designed to work with Mil-Spec lowers
  • Does NOT include last round bolt hold open
  • Works with Glock® 17 and Glock® 19 mags
  • Built of 6061 aircraft-grade aluminum
  • Does not include last round bolt hold open


  • Material: Steel and 6061-T6 Aluminum
  • Finish: Black Anodized
  • Weight: 4.2 oz.

DISCLAIMER: This product is not manufactured, authorized, endorsed, or warranted by GLOCK. GLOCK does not warrant or represent that this product is compatible with GLOCK pistols.

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