This versatile tool will provide cardio training and power training, at the same time. The specialty of the Easy grip ball is in its texture, which makes it easier to hold, while the quality rubber prevents rebound.Circumference: 75 cm (from 4 kg to 10 kg), 92 cm (12 kg), 93 cm (15 kg), 95 cm (20 kg), 97 cm (30 kg), 110 cm (40 kg), 112 cm (50 kg), 114,5 cm (60 kg) The Slam Ball is currently available in blue and black. When the stock of blue balls runs out, only black balls will be available. If you order more than one Slam Ball in the same order, we will try to ship them all in the same colour. If you have specific requirements and would like to receive a particular colour, please contact us and we will arrange it. *Note: Black Slam balls have a special impregnation to protect the rubber. Before first use, you will need to wash it in warm water and the grey coating will come off, so after cleaning it, it should be black.