$80 - great condition $90 shipped Product Details: Model: Std, ARMS 38 Swan, 5.56 cal, w/ intergal ARMS 40 sight 5.25" of Picatinny Rail, 7.25: o.a.l. The patented Swan Sleeves by A.R.M.S., Inc. - for all mil. spec. flat-top upper receivers - provides a platform for a variety of scope mounts via the A.R.M.S. standard mil. spec. dovetail type rail system. In addition, they incorporate a unique flip-up rear sight (shown here in "up" position) that aligns with the existing front sight; always stays in battery and can't be knocked down by accident. This rear sight provides an A2 type windage adjustment with std. 250-300m range zero and a new 500m horizon line setting.