Strength training with kettlebells can do wonders for your body. Kettlebells are not particularly expensive, but if you already have dumbbells, why not use them as kettlebells? The KettleShell makes that possible. It has a strong shell that locks the shaft of your dumbbell. The handle lets you use your dumbbell like a kettlebell. Why buy more weights when you can already put your dumbbells to good use.