Three (3) 4-inch diameter by 3 1/2 inches tall with a 2 3/4-inch opening at the top and a flat bottom for stability. You can put a small bouquet of fresh flowers in it for a festive table decoration, a beginner bowl for a new fish to adapt before it is put into your aquarium , a floating flower, or a small candle like a tea light or votive candle for accent lighting during a meal. They are clear glass with no chips, scratches, or cracks. I found a posting on eBay for $4 each or $47.95 for 12, but you can have all three for the $5 price.