Lava rocks and solid steel grate included. Ventless Fuel comes in 13 oz. SizeLarge 23-1/2" x 12" x 12"H Small 18" x 10-1/2" x 12"H. A stay-cool handle helps you lift the logs to refill the concealed fuel holders. canisters. Large holds three fuel canisters. Create the look and feel of a real fire in any fireplace with our ceramic Gel Burner Logs.