[safe material-thick version] 2m
[safe material - thickened version] 2m +4 anti-collision corners
[safe material-thick version] 5m
[safe material - thickened version] 5m +10 anti-collision corners
[safe material-thick version] 10m
[safe material - thickened version] 10m +10 anti-collision corners
[safe material—thickened type] 20m
[safe material—thickened type] 20m +10 anti-collision corners] 20m +10 anti-collision corners