The brown leather is called a leather guard and us used to protect the cosmetics from the sharp fiberglass bodyshell, and the black plastic tube is used to protect the cosmetics from the sharp metal mech along with give the characters arm a better shape than the skinny metal robot arm of the mech.

Leather guard and arm duct

Arm ducts.

They’re typically air ducts, used in buildings on the ceiling

They’re just tubes, you can find them at your local Lowes

Pauldron? Shoulder pads? And the black things tubes maybe?

Vaccum

lether gaurds brown thing and arm ducts black thing