The Mr. Pen biodegradable dog poop bag is made of environmentally friendly material, which is biodegradable to help protect the environment. Each dog poop bag measures 13 x 9 inches, which is large enough to tie and pick up more pet poops. The poop bags for dogs are durable and leak-proof. Each bag has some tiny connections with the next one. It is easy to tear off and not rupture the bag because of its thickness.