Sorzy Combo 11,14,16,18 Steel Finish Number Needle for Domestic Sewing Machines, Needle Type : One Side Flat (Pack of 4, 40 Pieces) Made of Premium Strong Durable Stainless Steel. Comfortable and sturdy, for long time usage. Bright and shiny. The shank (top part) of needles have one flat side, enlarged eye and widened groove which protect fragile threads and guard against excess friction. General purpose needle that can be used on most knit. 11 No Needle is Suitable for medium fabrics, cotton, linen and satin. 14 No Needle is Suitable On All Types Of Cotton Cloth, Hard & Heavy Clothes Types( Not Jean Cloth) 16 No Needle is Suitable for All Types Of Cotton Cloth, Hard & Heavy Clothes Types, Canvas, Cotton Duck, Sail Cloth, or Upholstery Fabric, and on thicker projects such as Purses. 18 No Needle is Suitable for All Types Of Cotton Cloth, Hard & Heavy Clothes Types ( Not Jeans Cloth)