Towa L-Style Towa Sewing Thread Bobbin Case Tension Gauge TM-1 Price is for 1 Towa L-Style Towa Sewing Thread Bobbin Case Tension Gauge TOWA1-L L-style Towa Bobbin Tension Gauge (TM-1) is designed for use with the following longarm machines: APQS, Nolting (most models) and Voyager TOWA Bobbin Tension Gauge is designed for mid-arm and longarm machines; measures bobbin thread tension for ideal stitch quality. TOWA Bobbin Tension Gauge makes it very easy to adjust bobbin tension by giving a numerical range to how tight or loose the tension is in a bobbin case