View All › Syringes - Pack of 20 Image 1 of 1 Syringes - Pack of 20 $5.00 1 mL 5/16 Inch 31 Gauge Insulin Syringe used for administering peptide injections. Add to Cart Added! 1 mL 5/16 Inch 31 Gauge Insulin Syringe used for administering peptide injections.