The entire model # is 158.17520. The 158 series Kenmores are some of the best machines you'll ever run across. Your particular model has the little needle plate that you can switch from straight to zigzag. If your's is scarred up, they are available on ebay. It also takes a standard low shank foot...also easy to find. I have a 158.17550 that I've used HEAVILY since 1969...made all my clothes, all the kids clothes, all the ex-husbands shirts....& had a home sewing business for several years. It's still my go-to machine....& still sews like new! And sooooo smoothly! Mine also has the switchable needle plate & it's really handy for lightweight fabrics...using the straight stitch side gives you wonderful control and keeps very lightweight fabrics from wanting to go into the needleplate hole like they sometimes like to do with a standard zigzag plate. Get it cleaned up & oiled & you'll love it!