The descending bubbles have a soothing and mesmerizing effect that will keep kids entertained for hours. ^Gravity will guide the colored droplets travel down at slow motion space. These sensory toys can help improve visual tracking skills. Its slow and rhythmic drops have a very appeasing effect and actually help kids with sensory or hyperactivity issues. ^Makes perfect autism sensory toys to sooth and remain focused. Endless hours of calming entertainment. Great as therapy toys and even stress relief toys. ^Never runs out of energy. Just flip over and start again. This liquid timer makes the perfect fidget toys, office desk toys and even as classroom rewards. Like a stress ball used for hands, these are perfect as ADHD toys for gentle visual stimulation.