The LK-140 & LK-150 are similar in design, with one having 140 needles and the other 150 needles. The needle spacing of 6.5mm is the same on both machines. The needle hooks are slightly different in size an the transfer tools have different size openings. The major differences in the machines is in the carriage operation.
The LK-140 has seven tension settings with one click between each setting. The LK-150 has nine tension settings with one click between, plus an every-other-needle setting for tensions. 10 thru 13. This carriage was designed to closely match the size of hand knitting needles. Also, the yarn feeder on this carriage has a slight projection to hold the yarn in the feeder more firmly. The LK-140 has pink and white rollers on the needles, setting the needles in groups of 5; the LK-150 has groups of 10. These rollers can be repositioned to mark stitches for hand operation. The roller cam can be removed by putting a finger over the needle shank and pulling up gently on the roller. You can then trade colors in the same areas where you wish to reverse a stitch, or set up the sequence for the design on which you are working.
The LK-140 and LK-150 have a tension pole setting which matches the tension setting on the dial so that various yarns will be held securely. An additional yarn clip at the end of the machine will hold yarns which you want to keep threaded but are not in use on the machine