These tattoo tongs have a "positive ear release," a spring-set metal plate that helps push ear free when tongs are released. Ear release is useful with Nubians or adult goats; not as convenient for kids with very small ears.The 5/16 inch tattoo tongs hold up to five digits. Smaller than standard cattle tattoo tongs, but tattoo marks are still easily readable. Convenient for use on small kids. Digits have rust-resistant nickel-plated needles. The tab-and-slot design means you can't insert digit upside down. Made of strong lightweight aluminum, 8 1/2" long; head is 2 1/4" wide; throat of tongs is 2 1/2" deep. Tattoo tongs are conveniently sized for goats; large enough to use on calves. 5/16 inch digits are too wide to use in the .300 tattoo tongs. Order alphabet letters separately.