... material.Features:1) Model 97-4301: a) Glass dropper 3" straight, 12/pk b) Quality black rubber ... black rubber bulb3) Model 97-4401: a) Glass dropper 4" straight, 12/pk b) Quality black rubber ... bulb4) Model 97-4402 : a) Glass dropper 4" curved, 12/pk b) Quality black rubber ... bulbPacking: 12pcs/boxWe have many other lab glassware, including stain dish, glass stirring rods, ...