Specification BatteriesRequired : 1 Brand : Taidacent BulletPoint1 : Proximity sensor: only sense metal objects, sensing distance 0-5MM BulletPoint2 : Hall sensor: Only sense magnetic objects, such as magnets BulletPoint3 : Photoelectric sensor: sensing distance 0-30CM, sensing all opaque objects BulletPoint4 : Memory:40 Points BulletPoint5 : Auto Power Off:Aotomatically after approx. 30s ExternallyAssignedProductIdentifier : 9336306934345 ExternallyAssignedProductIdentifier1 : 0792323452917 ExternallyAssignedProductIdentifier2 : 792323452917 ItemName : Taidacent Motor Speed Tachometer Measuring Instrument Digital Object Counter with Photoelectric Sensor/Hall Sensor/Proximity Sensor (Hall Sensor) ItemPackageQuantity : 1 ItemTypeKeyword : industrial-tachometers Manufacturer : Taida Material : Plastic ModelNumber : ST-722 NumberOfItems : 1 PartNumber : ZC-Speedsensor-0109 ProductDescription : Proximity sensor: Only sense metal objects, sensing distance 0-5MM Hall sensor: only sense magnetic objects, such as magnets Photoelectric sensor: sensing distance 0-30CM, sensing all opaque objects