G21 G90 G17
G0 X0 Y0 Z0
F100
G41 D1
G1 X20 Y0
G1 X20 Y20
G40
G1 X0 Y0
G42 D1
G1 X20 Y0
G1 X20 Y-20
G40
G1 X0 Y0
G41.1 D6
G1 X20 Y0
G1 X20 Y20
G40
G1 X0 Y0
G42.1 D6
G1 X20 Y0
G1 X20 Y-20
G40
G1 X0 Y0
M30