Matfield is 2m tall and about 110kg with a couple of weights down his armguard.
From the nzherald.co.nz
He was allowed to play with a leather armguard on his return but never regained his top form, much like the All Black side after their win in the second test.
From the nzherald.co.nz
More examples
Bracer: a protective covering for the wrist or arm that is used in archery and fencing and other sports
Protective padding located on the batsmans front forearm.
A device worn on the inner side of the bow arm to protect the arm from the slap of the bowstring.