... current < 5mA dynamic current < 30mA4 This handheld needle detector can work for a long time. No ... which without any metal. Use the handheld needle detector to detect the surface of the object ... up and down. Detection rangeUse for detecting the broken needle of all knitting, costuming, shoes, socks, quilt ... . To prevent battery leakage destroy the handheld needle detector, Please take out the battery for ...