Weight Engravement All kettlebells display their weight in kilograms and pounds so you always know which weight you are working with in either measurement. No Welded Rod Our kettlebells never contain rods in the middle of 'unfilled' kettlebells that are known to distract lifts and vibrate with impact. No Fillers Each weight 4 to 36 kilograms has an individual mold cast precisely to the correct weight and contains no fillers, except for kettlebells 40kg and above. 35MM Handles & Color Standard Handles are 35mm according to international competition standards. Kettlebells match international weight color standard.