These cups come in two-packs. In the package we purchased, the Dora the Explorer design, one cup is purple with a green lid and green bottom and the other is green with a blue lid and bottom. They sport cute character designs on one side a "This cup belongs to:____" tag on the other side. Ours were Dora the Explorer, but the cups also come in Sponge Bob and Diego. The cups hold 10 ounces and are insulated. The recommended age group for these cups is 2+ years. The valve mechanism is a flexible, rubbery material.
My daughter has been using this cup for 5 months, since she was 22 months old. My daughter, of course, loved the cup as she is an avid Dora the Explorer fan. It is also easy for her to hold, a good size for her little hands. The spout is a smooth, curved plastic that is easy to drink from. We also like the rubbery bottom, which prevents it from tumbling of the table onto the floor too easily. The insulation of the cup works wonderfully. Our daughter insists on bringing a drink to bed with her at night- and it must be cold. We put a couple cubes of ice in with her water when she goes to bed at 8pm and it is still cool the next morning at 8am.
The only issues we have had with this cup are very minor. When we first used the cup we had problems with it leaking, but we found that the problem was not the cup, but the way we were inserting the valve. We were putting the valve onto the notches on the lid, but not pressing it into place. It needs to be pressed firmly into place so that the two notches on the spout opening emerge slightly from the holes in the valve sides. Pictures of the valve and the lid are included for reference. The only other issue is the picture fading or chipping away. After five months of regular use a very small amount of the Dora images are wearing off, which is to be expected.
Overall I have found this to be an excellent cup. It is definitely my favorite cup to use fro my daughter, and I have tried many. It also is a favorite of hers with the bright colors and character designs.