here
p -2 -0.5 0
p 2 -0.5 0
p 2 0.5 0
p -2 0.5 0

p -2.5 -1 0.5
p 2.5 -1 0.5
p 2.5 1 0.5
p -2.5 1 0.5

mtl metal_yellow
f 0 1 2 3
f 0 1 5 4
f 1 2 6 5
f 2 3 7 6
f 0 3 7 4