Made in China ST-30C Detecting method: Magnetic induction Detecting ability (2 adjustments): - Low mode: Fe 1.0mm sphere or above, at 5mm height from detecting surface. - High mode: Fe 0.8mm sphere or above, at 5mm height from detecting surface. Detecting area: 25mm (width) x 50mm (depth) Alarm method: Buzzer & LED Lamp. Dimension: 58mm (W) x 195mm (L) x 50mm (H)