Thank you for visiting, so happy you're here :-). This is a brand new set!! The Pet Supplies Plus Play-On Waterproof LED Safety Dog Collar Large AND a 4 ft Lead Leash for Dogs 20-90 lbs by Grrreen. I was buying birdseed to feed the birds, saw these and thought they were cute together and I hadn't seen an LED collar before so I wanted to get it to share it with you. The collar is waterproof, with a soft rubber-like touch when feeling it. The lights (light up feature) run on a battery from what the lady in the store could tell me, although the casing doesn't say anything about it; she opened one not lighting up to check and relayed it was a button / watch coin battery. THAT'S ALL I KNOW :-)!! I'm not turning it on a lot but when I light it: first click turns lights on; second click is a color flash; third is a rapid pattern flash; and the fourth click's off. It's cute! Web sizing details says it's 1 In. x 18-26 In., but as far as battery, sorry I just can't see which kind. The 4ft leash made from recycled bottles feels really durable. Adorable set! NOTE ABOUT MY ITEMS: I'll always do my best and I hope it shows that I truly love what I have and find and it's not without energy that I do this. I work hard on this stuff, it's not easy or cheap. I'm NOT a professional seller and absolutely NONE of this is drop, or bought in bulk or online so I can't price according to anyone else, only what I pay and my own receipts. Thank you for your understanding and support!