1. Max detection depth: 1.5 meter2. Power Supply: 8pcs 1.5V Batteries in Series3. Emitting Signal Frequency: 6.99+/-0.2KHZ4. Audio Signal Frequency: 450HZ+/-10HZ5. Indicators: Visual: Lever MeterSound: 2" Speaker or Earphone(Earphone not included)6. Function: Disc: Ground Balance ControlsDistinguish Ferrous and Non-Ferrous Metal 7. Controls: Critical Sound Tuner; Function Tuner;8. Operating Current: 300Ma MAX at MAX Volume 9. The Detecting Depth (Max): 1.5-2 Meters10. Sensitivity: 25-30cm for a US(25cent) 11. Export Packing: 4PCS/Carton 0.1736CBM (64*32*85cm)12. Color: Black13. Certification: EMC Certification14. Attached: external battery box and bagEach detector is attached a piece of guarantee and it is free to be repaired during the length of warrantee unless he circuit is changed by user himself.