Passap Yellow Tool Is Now White: The Passap Yellow Tool (now white) is one of the most used tools for the Passap knitting machine. One end is a latch tool. The other end is a double decker needle. The original version of the yellow tool is the green tool which has only one decker needle. (Also available on this site). The latch end of the yellow tool is used for double bed bind-off, and for repairing dropped stitches. You can also use the yellow tool latch to sew up and attach pieces. If you are shaping, it's handy to have a tool at each end of the bed.