Specifically engineered for the storage of histology specimens O-ring polyethylene screw cap forms a seal that reduces most formalin leakage and evaporation Durable polypropylene containers are translucent, flexible, resist cracking and splitting, and eliminate problems associated with formalin evaporation 40mL to 1L containers have graduations for easy fill line viewing 2 to 8L containers are white polypropylene with unique tamper-evident snap-on lids