It's like an insulated lunch box you Velcro attach to your Baby Jogger stroller. So so handy! Nice and big, holds a lot. A great accessory to your day and stroller. Dimensions are approximately 16 inches x 5 x 3, with room to give. Zipper closure and Velcro with hook attachment so it stays put. Baby Jogger calls it their cooler bag. Features & details Keeps food and drinks cold while you're out of the house Holds up to 6 small baby bottles and a 12 oz. can Easily attaches to rear stroller crossbar compatible with:city mini, city mini double, city mini gt, city mini gt double, city premier, city select, city select lux, summit x3, summit x3 double