1. suitable for use with both air and saline techniques with standard luer slip connection to epidural needles; 2. designed with low and consistent frictional movement of the plunger to provide excellent sensitivity for epidural space detection; 3. with loss of resistance (lor), the original resistance is up to or less than 0.3n, the resistance of process is about 0.2n; 4. with complete specifications, the main specifications are 5ml and 10ml; 5. obtained quality system certificate for iso13458, iso9001, and ce certificate; 6dundertake oem orders.