U-40 INSULIN SYRINGES AVAILABLE IN 3 SYRINGE SIZES: 31G 3/10CC OR 1/2CC WITH 5/16" NEEDLE NEW! 30G 1/2CC WITH 1/2" NEEDLE For small and medium sized dogs, PetTest U-40 insulin 31 gauge syringes are the WORLD'S THINNEST, which provide a more comfortable injection for your customer's pet. All other U-40 syringes available use a thicker, less comfortable 29 gauge needle. Designed for use with all U-40 insulins, all 3 sizes of PetTest U-40 syringes feature ½ unit markings for accurate measurement and delivery of any dosage size. The shorter 5/16" needle length also minimizes the risk of a painful injection into the muscle. For larger dogs with thicker skin, we now offer a 30G syringe with a 1/2" needle. FEATURES 31G x 5/16" for comfort and less pain NEW! 30G x 1/2" for tougher skin on larger dogs ½ Unit Markings for Precise Measurements Fine, Sharp, Extra-Lubricated Needles Tri-Bevel Tip for Greater Comfort Extra Wide Finger Grips Protective Needle and Plunger Caps