1. Shell stitch type 2. Different thread 3. 1 stitch, 4 stitch ... . Heavy duty JJ-38 heavy duty shell stitch glove sewing machine .Application: .Suitable for big shell stitch decorative sewing for sweater, coat ... , etc. .Feature:.Different thread, materials and stitch length collocate diversification shell stitch style.1 stitch, 4 stitch and 8 stitch pattern ...