We miniaturized some some of the basic circuitry of SMTcylon and came up with BlinkyBall. Just 14mm square. It’s a motion activated ball, multi color, with 4 integrated programs: short, medium, long, and sleep. Drives cates nuts!
BlinkyBall is just 5$ as a kit, or 7$ assembled. Each comes with a battery. Spare batteries are CR1221 and available at your local drug store, or here 5/2$. Due to current TSA rules, batteries must be shipped by ground.
SMTblinkyBall Kit $5ea/w battery:
SMTblinkyBall Assembled $7ea/w battery:
CR1221 Batteries $2/5: