Before and after each use, wash Breast Shell parts in warm, soapy water and rinse, or top-rack of dishwasher. Breast Shell parts can also be sterilized by placing in boiling water for 5 minutes. To assemble, affix silicone piece to back of Breast Shell. Make sure it is sealed all the way around. Insert assembled Breast Shell into bra and center opening in silicone piece over nipple. Ensure air holes are positioned upward.