Purple activity meter made by OMRON, uses CR2032 batteries. - Brand: OMRON - Model: HJ-405T - Color: Purple - Battery: CR2032 - Country of Manufacture: China Thank you for viewing. I am selling this because I tried to use it, but I don't know how. I will include the instruction manual downloaded from the internet and the battery. There is no box. ☆ I have a long-haired cat. Please refrain from purchasing if you have allergies. Thank you very much. #Omron #OMURON #ActivityMeter