Polypropylene. The patented O-Ring polyethylene screw cap forms a seal that eliminates most formalin leakage and evaporation. The durable container is translucent, flexible, resists cracking and splitting and eliminates the problems associated with formalin evaporation. Histology Container, 250mL, Formalin Warning Label Included & O-Ring Cap, Yellow, 10 Sleeves of 10 Containers & 5 Sleeves of 20 Caps, 100/cs |