HRT Tactical Gear Maximus Inserts - SMG Black. This insert allows most size magazines to be inserted from a smaller MP5 (9mm) style magazine up to larger HK UMP (45ACP) style magazine. The inserts are elastic and if your magazine is similar in size to the ones pictured it will probably work. Hold up to 5 Magazines Fits Maximus Placard Elastic construction to fit most magazines NOTE: Only works with Maximus Placard System Specifications for HRT Tactical Gear SMG Maximus Insert: Manufacturer: HRT Tactical Gear Color: Black Size: One Size Fabric/Material: Elastic Quantity: 1 Condition: New Attachment Type: Velcro Package Contents: HRT Tactical Gear SMG Maximus Insert HRT Tactical Gear HRT-FPMXIN-SG-BK: Maximus Inserts - SMG Black