. Lightweight, American-made accessory for MS3, MS2, VCAS, and VTAC slings. Also includes the same detachable rubber buttpad found on Magpul CTR and UBR. Slot molded in the toe provides an attachment point for a 1¼" wide sling. Enhance your Magpul UBR with CSAP MOUNT-N-SLOT. Shop now at Ubuy Panama. Lightweight, American-made accessory for MS3, MS2, VCAS, and VTAC slings. Shop now at Ubuy Puerto Rico. Enhance your Magpul UBR with CSAP MOUNT-N-SLOT.