The Ketchum 101 Ear Tattoer is the most popular size for tattooing new born pigs (from 4 to 21 days of age), Also ideal for 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 each 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.