The Ketchum 101 Ear Tattoer is the most popular size for tattooing new born pigs (from 4 to 21 days of age), dogs, rabbits, goats, sheep, bears and other wildlife animals. Tattoo will grow with the animal and be easy to read throughout their lifetime. Character size: 6mm (1/4"). Forceps hold up to 7 characters in one row. Fast/easy tattoo character change. Comfort grip for easy long term use. Proven over decades of use. Characters specifically designed to produce easy to read tattoo. Strong spring for quick release.