The Singer® Model 4423 Heavy Duty Sewing Machine is an all new heavy duty sewing machine from Singer has all the power of model 4411, but adds an extra 12 built-in stitch patterns for a total of 23 built-in patterns! The extra high sewing speed is rated at 1,100 stitches per minute! Other features include a top drop in bobbin system for Class 15 bobbin and a fully automatic 1-Step buttonhole. This machine packs the power and speed to quickly take on any sewing project. You can pretty much sew anything with this workhorse – from burlap to leather!