Diamond Shaped 12oz Stemless Plastic Wine Glass. Toast any occasion with our Diamond Shaped Stemless Plastic Wine Glass. This 355 millilitre plastic wine glass is a simple yet elegant alternative to glass stemware. Pop this diamond shaped purple plastic wine glass on a drinks buffet, use safely at an outdoor event, or buy more, and hand them out during a toast at a wedding or anniversary party. Best of all, this plastic wine glass is reusable, so can be hand washed and used again and again!