The siamang is an arboreal black-furred gibbon native to the forests of Malaysia, Thailand, and Sumatra. The largest of the gibbons, the siamang can be twice the size of other gibbons, reaching 1 m in height, and weighing up to 14 kg.
Siamang hands and feet are a lot like ours. They have four long fingers and a smaller opposable thumb on their hands, and their feet have five toes like we have, but their big toe is opposable, too. The opposable thumb and toe is lacking in other members of the gibbon family. Siamangs can grasp and carry things with BOTH their hands and their feet. One other thing that sets the siamang apart physically from other gibbons is webbing between their second and third toes.