Collect and Store pumped breastmilk easily. Safe Breastmilk Storage in refrigerator or freezer. Made of Polypropylene Plastic (PP), BPA FREE. Can be sterilized through steam or into boiling water. Pack of 4 includes: 4 5oz (150ML) Bottles 4 Screw Rings 4 Silicone Sealing Discs (100% Leak Proof Guaranteed) Compatible Breastpumps: Dula Mina Double Electric Breastpump Standard Neck Electric or Manual Breastpump Real Bubee RH228 Cimilre S3 & F1 (with adapter for standard neck bottles) Compatible Nipples: Pigeon Peristaltic Standard Neck Nipples Looney Tunes Standard Neck Nipples Farlin Standard Neck Nipples Bebet Standard Neck Nipples