The SINGER HD6600 Heavy Duty Computerized Sewing Machine offers 215 stitch applications including 6 automatic 1-step buttonhole styles. This machine is a true workhorse with powerful piercing power for thick fabrics or multiple layers and extra-high sewing speed. A top drop-in bobbin for easy threading and viewing and an automatic needle threader that quickly threads the machine making this the perfect machine no matter your skill level. Singer Heavy Duty 6600C Computerized Sewing Machine – New In Box. Has a big bump in it, does not affect product functionality. Great deal on a Singer product with great reviews.