This is the Rifle Mag Attachment for the Sidecar. As the name indicates, you'll be putting a rifle magazine in here. Rifle magazines though across the board have a lot of variance as far as whether they are a polymer based magazine, like a Lancer or a steel body, like a traditional STANAG, or like this SureFire 60. So what you'll be doing based on the magazine that you're using is you're gonna be utilizing the four screws located (two here on the side, one on the top, one on the bottom) to adjust the retention on the magazine itself. There's holes in front and back for the clip. So if you're wrong-handed or right-handed, you know, the clip's gonna go to either side. The magazine is also fully ambidextrous as far as the direction of the rounds. So if you want a rounds forward orientation you can do that. Rounds rearward. There you go. Just like so. To attach the rifle magazine carrier to the Sidecar, it's very straightforward, just like every other attachment. Slots right into the spine. Tension washer will go here in the center. Friction washer, tension washer. Take the pin, push it on in. And there we go. Now that is attached to the holster. I can then take my 300 Blackout 30 round magazine or my 20 round magazine, a little more comfortable. And I'm set. If you have any further questions about the Sidecar holster and these attachments, email us at [email protected].