Must Know before Purchase: Please long press the power button for 3-5 seconds to turn on this rechargeable knitting machine counter. And then the sensor tracks rows accurately and the display is easy to read while working. Row Counter for 32, 40 and 48 Needles: Foggizo Knitting Machine Counter is compatible with a wide range of circular knitting machines, including 32, 40 and 48 pin models. Overall it is a useful tool for keeping track of rows without manual counting. Rechargeable Knitting Machine Counter：Plug in and have this knitting machine counter charged.