Dear，Pls leave a massage to tell us what design (Color) do you want.thank you.

Wrist ball doesn't need battery， it is powered by rotating the wrist， all you need do is to increase the speed by making a rotational wrist movement and the speed of rotation can reach up to 12，000 R.P.M. The Forceball can generate between 1 and 30 pounds of resistance by spinning at almost 12，000 rpms.The faster you spin， the harder your muscles exercise. and when you spin the LED lights inside the ball will be flashing.Function:Perfect exercise gadget for sports like golf， tennis， squash， cricketm badminton， baseball， bowling， basketball， motocross， mountain climbing.Increases strength in fingers， wrists， hands， forearms， biceps， triceps， ligament and shoulders.Great benefit for musicians， guitarists， pianists， drummers.Color: Blue， Green， Purple， Red， Yellow， Crystal (We send the color at randomly)Package include:1x Forceball with LED speed meter1x Starting rope1x Hand strap1x User manual