Adjustable Kettlebell vs Standard Single Cast Kettlebells. Adjustable kettlebells have all of the advantages of standard kettlebells but with the added benefit of saving you space and money. Even though, both standard grade (iron) kettlebells and pro-grade (steel) kettlebells are lightyears ahead of any type of adjustable kettlebell, I only fully endorse and recommend professional-grade kettlebells. It’s a cute addition to the line-up, looking something like sports equipment and something like a milk jug, but there’s no doubt it offers a versatile- if not slightly awkward- adjustable weight. Black and grey are the most common options but it is not impossible to find blue, red, or even an adjustable kettlebell … Kettlebell size between 5-15lbs (2-7kg) for kids of age 9-11years. The kettlebell size recommended for kids is based on their age, and the recommended dimensions are: Kettlebell size between 5-8lbs (2-3kg) for kids of age 5-8years. If you’d like to know why these are the best type of kettlebell, then please read my First Time Kettlebell … Kettlebell … For those of you who may not have discovered the wonder of a kettlebell … If you want to train seriously with kettlebells and have the proper feel, grip and design of a true kettlebell, the standard single piece kettlebell … Most standard kettlebells are found in pure black, unless they are competition bells, but you can find almost any color you want in traditional or adjustable kettlebells. With its fillable body design, the Crossbell Kettlebell …