... helps column, channel pedal, railway, high CeDao floor drain cap, platform scale, covers the grille, stereo, road parking lot, organs, schools, ... centers:15-30, 40, 60, 80, 90 mm etc. with 30, 40 mm recommended.Cross bar centers:any greater than ... 30mm is ok. with 50, 100mm recommended.Surface treatment:G - galvanizedP - paintedU - untreatedGrating ...