Size: see in the pic Material: Resin Quantity: 30pcs the rf19-1 don't have middle stud, others are plastic pearl inside The color will be a little different due to the light and condition when taking the picture. You need to use glue to stick on nails. also you could use them on cellphone case too. They are pretty cute when you DIY your nails ^_^. Feel free to contact me if you have any questions.