Model : BT-C101B Standalone (Whit LCD) Detection Mode: Electrochemival Sensor Battery : DC4.5V (3XAA1.5V) Volume: >85dB (1M Distance) Sensor : Electrochemical Lifetime : 10 Years Certificate :Interetek , ISO9001 , CE , ROHS Dimensions: 140*66*35 (mm) Weight: 196g (Battery Included) Model : BT-C101A Standalone (Without LCD) Detection Mode: Electrochemival Sensor Battery : DC4.5V (3XAA1.5V) Volume: >85dB (1M Distance) Sensor : Electrochemical Lifetime : 10 Years Certificate :Interetek , ISO9001 , CE , ROHS Dimensions: 140*66*34 (mm) Weight: 188g (Battery Included)