If you want your kids to develop good and healthy brushing habit, this electric toothbrush might be a good choice as a entry level one. 

Features: 
IP-X7 waterproof. 
Ergonomic skid resistant handle. 
Healthy food-grade, soft silicone toothbrush's head. 
Compact and light weight design, portable and more convenience for using. 
Cute color and style, which encourage kids to develop healthy brushing habits. 
Sing toothbrush, surely kids would enjoy brushing their teeth while listening music. 

Specifications: 
Color: Pink / Pink blue / Pink green (Optional) 
Material: ABS + Silicone(food-grade) 
Target User: Children aged 3~5 
Power Suply: 1 * 1.5V AAA Battery (not included) 
Item Size: Approx. 18.5 * 3cm / 7.28 * 1.18in 
Item Weight: Approx. 40g / 1.41oz 
Package Weight: Approx. 130g / 4.59oz 
Package Size: Approx. 7.3 * 23 * 3.7cm / 2.87 * 9.06 * 1.46in 

Package List: 
1 * Electric Toothbrush 
1 * Cap