The Priority Mail Regional Rate Box - B1 (Top Loaded) is a quick, easy, and convenient way for you to ship USPS Priority Mail packages. It is a top-loading box for up to 20 pounds. (Handling fee applied at time of purchase)
Inside Dimensions: 12" x 10-1/4 x 5"
Outside Dimensions: 12"-1/4 x 10-1/2" x 5-1/2"