1/8” & 1/16” thick The Hump Jumper is a seam jumper or seam aid that is used to ease the presser foot up and over a particularly thick spot. Simply slip the Hump Jumper under the back of the presser foot on top of the fabric to get up and over the "hump". It eliminates skipped stitches, stitches of uneven length, and broken needles.