Abstract: An elastic lid for application in closing relation with various beverage containers is of silicone rubber, with a resilient, stretchable diaphragm-cover portion with a down-turned rim, which enables its use with a range of sizes of containers. The rim has peripheral sealing ribs, and includes pull-tabs, to facilitate installation/removal. The lid has an upstanding mouthpiece located adjacent its rim, with a few, restricted apertures which limit the beverage drinking or spillage rate. An oppositely-located air vent hole may be provided; also the cover surface may be ribbed. The slim profile and flexible nature of the subject lid suits it for being carried in pocket or purse, within a protective envelope.