Duo covered by Packaging Digest
Aimed directly at bottled water applications, the Duo debuts as a closure with two silicone one-way valves that reportedly enable sanitary sharing by allowing the product to flow only in the outward direction with no backwash, no spillage and no leakage. The Duo and the Duo lite patent-pending versions have closures that are compatible with existing capping equipment and cost a fraction more than a regular sports cap, the co. reports.
See article at Packaging Digest: http://www.packagingdigest.com/