ISS Series ISS STEEL SQUARE W/BASE. Description ISS STEEL SQUARE W/BASE ISS-03: 3"/ 75mm ISS-04: 4"/ 100mm ISS-05: 5"/ 125mm ISS-06: 6"/ 150mm ISS-08: 8"/ 200mm ISS-10: 10"/ 250mm ISS-12: 12"/ 300mm ISS-14: 14"/ 350mm ISS-16: 16"/ 400mm ISS-18: 18"/ 450mm ISS-20: 20"/ 500mm ISS-24: 24"/ 600mm View More Details