The CarePoint Vet U-100 Pet Syringes 31G 1/2cc 5/16" Case of 500 provides large, bold, easy-to-read permanent markings for accurate dosage and lubricated needles for injection comfort. For use with U-100 Insulin ONLY. Features: Comfortable finger grip for better injection control. Permanently attached needle. Clear bold gradation for easy reading. Permanent barrel markings to assure accurate dosing injection. Lubricated needle for smoother injection. Easy to red tri-lingual package. Case of 500.