Durable, lightweight and battery-operated.Once secured, they don’t need to be removed.Tru-Test Active Tag Ear TagSKU : 700 2100-746Weight~25-30g Dimensions36.9mm x 14.5mm x 68.4mm Compatible withZ Tags male tags and No-Tear-Tagger™ Battery life3 years warranty Light indicatorLED Reading distance to ATG gateway500m Radius