I've utilized this equipment gently for about 10 years. It's well made, trusted and clean, in "fresh" condition. You can access the manual right here (and I have a paper copy of it that chooses the device): /manual/150314/Sears-Overlock-3-4d-1.html
Here is the listing for the specific very same machine that offered just recently on Ebay for $149 plus shipping: /itm/Kenmore-Overlock-3-4D-Serger-Differential-Feed-Model--/?nma=true&si=bY8jLmFmDVJkTNK6ZtV1KxLf8kU%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557
Has a metal power pedal and original box with styrofoam inserts in case you ever have to move it or ship it. Come give it a test drive! Cash / regional sale just. Cost is firm.