FAB Defense MPS-12 Magazine Extension 4 Rounds M&P9 SHIELD Black fx-mps12b. The FAB Defense M&P 9 SHIELD Polymer Grip Magazine Extension adds 4 more rounds to your Smith and Wesson magazine in a way that maintains its low profile. The special ergonomic design enables secure manipulation of the magazine and a full grip on the weapon when the magazine is in use making the FAB Defense SHIELD Grip Magazine +4 Extension Grip a must-have for those situations that conceal-and-carries like the M&P 9 SHIELD were made for. Specifications for FAB Defense MPS-12 Magazine Extension: Manufacturer: FAB Defense Color: Black Magazine Capacity: 4 Round Gun Make: Smith & Wesson Gun Model: Smith & Wesson M&P Shield Condition: New Features of FAB Defense MPS-12 Magazine Extension Adds 4 rounds for a total of 10 rounds in the magazine Enables a full grip on the handgun Contoured finger indents for a firm grip during magazine manipulation Innovative spring plate allows the use of the original magazine spring Fiberglass reinforced polymer construction Smith & Wesson M&P 9 SHIELD Package Contents: FAB Defense MPS-12 Magazine Extension What firearm models does the manufacturer say FAB Defense MPS-12 Magazine Extension is compatible with? The manufacturer says that FAB Defense MPS-12 Magazine Extension is compatible with Smith & Wesson M&P ShieldFAB Defense fx-mps12b: MPS-12 Magazine Extension 4 Rounds M&P9 SHIELD Black