MR3810A (Switch) MR3810B (No-switch) 2.4GHz Active Tag Specifications Model name MR3810A (Switch) MR3810B (No-switch) Card shape Card Frequency range 2.4GHz Induced mode Auto-induced,timing transmit after outside factory two seconds Identified distance 3-80M Material PET,heat-proof,water-proof Dimension 87*55*5.5mm Weight 20g Battery Inside button lithium, CR2032 can use two~four years