The frame provides a means of carrying heavy bulky loads. The two sides and the top part of the frame are made of a continuous length of aluminum tubing bent to the required shape. There are two flap aluminum pieces that are riveted horizontally to the tubing or attaching the cargo support shelf. The top horizontal part of the tubing has two metal loops riveted to it for placement of the shoulder straps. There are two plastic grommets on the lower top frame for attaching the loop end of the shoulder straps. Aluminum Tubing. Forest Green in color. Weight is 1.4 kg (3.1 lbs.)