There are 3 different levels of resistance available which will allow children to progressively strengthen their grip and the muscles in their hands and wrists as they hold, squeeze and twist. 
Soft-resistance squeezer (6.5cm x 1.3cm thick)
Medium-resistance squeezer (6.5cm x 1.3cm thick) 
Hard-resistance squeezer (6.5cm x 1.3cm thick)
Ideal for ASD children as a calming tool or for sensory needs