i bought these for my boys and they love them. They are super easy to fill up. Which it comes with a little funnel so it makes it easier to fill with water. When putting it in the freezer make sure it’s on a flat surface. Once they are frozen completely they are easy to take out. They do take a little bit longer to melt than regular ice cubes so your drink does stay colder a little bit longer. My youngest loves to chew on ice cubes and he had no problem breaking the skull cube with his teeth. I highly recommend theses for anyone who loves skulls, Halloween or for there kids.