The Advanced Venipuncture Training Aid allows educators and trainers to teach sound phlebotomy techniques on lifelike models that include four visible and/or palpable veins of varying size and depths. Three veins, each of differing diameters are embedded in a semi-transparent, tissue-like material. The forth vein is deeply placed to simulate the variations in patient anatomy phlebotomists regularly encounter. A physical "pop" is felt as the needle enters the vein, followed by a realistic "flashback" of simulated blood, confirming the proper needle placement. An optional carrying case, with storage pouch for supplies is available (not included) for purchase separately. Manufacturer's estimated durability: 3600 punctures. NOTE: Not suitable for needles larger than 21 gauge (22- or 23-gauge recommended).