101-T Feature: Physical: Durable alloy case with stainless steel contactor, built-in flexible silicone layer, internal circuit board epoxy hardened, which completely resist drops and water-proof. Specific low voltage design, 3.6 V lithium battery, supports 700, 000 continuous readings. Storage: 10, 000 records. ( expandable) Operating temperature: -40 ~ 90 Won’ t lose data when power out. Specific design to prevent repeated readings. LED and buzzer to prompt success read. 7. Automatic alarm when low power or storage full. Data downloader Dimension: 10* 10* 3.5( cm) Weight: 140g Material: Alloy Power: 6V , 50HZ Operating temperature: -400C~ 900C Function : Communicate with the computer via USB connector , high-speed , stable transmission and data transfer Checkpoint HUA-90A Type: 1990A-TM Button, global unique ID( unmodifiable) Physical: Electronic chip stored in the stainless steel case that is water-resistant.strong & durable. Install on wall or equipment etc as a checkpoint. Entire stainless steel body, great concealed, waterproof, Long life> 20 years Patrolman HUA-90B Type: 1990A-TM Physical: Electronic chip stored in the stainless steel case , water-resistant.strong & durable. Used as patrolman identification.