Brother Coverstitch Bias Tape Binding Set XB3387001Brother Coverstitch Bias Tape Binding Set XB3387001 (SA230CV). For folding and attaching 6 mm(1 4) or 12 mm (1 2) bias tapes to fabric edge. The two piece Bias Tape Binding Set is used to fasten bias tape binding to the edge of fabric. This set contains a wide guide for wide bias tape that you will stitch on with the 6mm cover stitch and a small guide for narrow bias tape which will be stitched on with the 3mm cover stitch. You may also use the chain