19G Half-inch Dispensing Needle Blunt Tip with Luer Lock

0.5'' 1/2 Inch 19G Glue Dispensing Needle

"Spiral" Dispensing Needles

Dispensing needle hubs are commonly designed with a double-helix (spiral) luer lock mechanism to screw securely onto a syringe. This design provides a more secure connection than a simple "luer slip" fitting, which pushes on without twisting. This prevents fluid leakage and ensures a more precise application during dispensing. 
For a 19G half-inch needle, the "spiral" feature is the double-helix luer lock on the hub that attaches to the syringe.