WHEATON® Glass Serum Bottles, 500mL or 16.9oz, Clear Finish, Type I Borosilicate Glass. (500 mL Serum Bottle, Type I Clear, Molded Grads) 500 mL Serum Bottles, Type I Borosilicate Glass, Molded Grads. Raised graduations indicate approximate capacities in milliliters. Accepts standard stoppers and seals. Manufactured from 400 borosilicate glass that conforms to USP Type I requirements.