This is a simple coupon from ecomelectronics.com which sells batteries the original sizes for Omnibot 5402 and Omnibot 2000 And standard 12v 7ah or 12v 9ah SLA gel cell non spill able batteries used in all kinds of robots. I am in no way affiliated with this company but I've made three happy purchases and wanted to spread the savings. In the USA they have offered free USPS shipping for orders of two batteries or more lately as well.