http://www.toysrus.com/product/index...ductId=2850498
"When we tried these out on pre-schoolers rifles in 300 Winchester, they worked remarkably well. However, caution should be exercised when using lasers around small children as they tend to leave the switch in the "on" position and thereby shorten battery life. Our school is now ordering more so that each child will independently have sighting capability for any new weapons he or she later procures. Thank you Toys-R-Us for stocking this hard to find item!"