MM BK1S Mag Sleeve

The MM BK1S Mag Sleeve does everything the Mag Base does — extending your BK1/BK1S/BK2S magazine to a comfortable 15-round capacity on the stock spring, no upgrade spring required — but wraps the whole magazine in a full sleeve rather than just adding a base, and builds in a dart indicator so you can check your remaining rounds at a glance instead of pulling the mag to look.

TPU feet on the bottom cushion the impact if the mag gets dropped, same as the base version. If you don't need the dart indicator or the fuller sleeve coverage, the plainer MM BK1S Mag Base covers the same 15-round capacity at a lower price. Available in Black, White, Orange, Yellow, Pink, Silver, Dark Gray, Light Blue, and Purple.