16 kg and 20 kg Sand Kettlebells
They are really good for travelling. They aren't the same as regular kettlebells, but you can do most exercises with them. The 20 kg is a little harder to use for cleans, overhead presses, snatches etc. since it is a lot bigger (think medicine ball with a handle) than a iron kettlebell. I got two 16 kg kettlebells to do cleans and overhead presses since the shape and size is easier to handle for those movements. I use the 20 kg for squats, swings, rows and deadlifts.