I bought the ACE brand bag for my Memphis windshield. Just simply remove the middle acorn nut, slide the bag onto the bolt and reinstall the acorn nut. There is a small piece of metal channel that fits over the existing chrome strip for extra support and alignment. Think it costs about $65. Part number in J&P cycle magazine is 830-447. I can put my wallet, cell phone, and check book in it with room to spare.