Nite Ize GlowStreak LED Dog Ball Disco Pack of 1

I cannot recommend this light up ball enough. It is THE ONLY ball that stays lit for a long time. Every night our golden retriever stands by the door where we keep that ball in a ChuckIt (fits perfectly). As soon as we open the door he tears outside waiting for his favorite part of the day. What I love most is that once the ball is activated (by bouncing once), it stays lit for 10-15 minutes. That staying time is important as we are able to find the ball easily if Milo doesn't see where it was thrown or got distracted. I have changed the batteries on them and it is very easy. Living on the ocean though where there is lots of salt in the air so that fact and having lots of use does take its toll on the balls so we have to get a new one every 6 months or so. Also, if they are dropped in the pool, they do not keep lighting up. On a side note, our kids used this ball for playing lacrosse at night and each took one to college to keep up the fun.