1.step irons with upstand for staggered manhole steps - part 2 : step irons to be set into prefabricated concrete units
人孔直立错列阶梯脚扣.第2部分：浇入混凝土预制件的阶
2.Step irons with upstand for staggered manhole steps - Part 1: Step irons to be fitted in masonry or set into concrete
直立双行程阶梯脚扣.第1部分：砌墙或浇灌混凝土的阶梯脚扣
3.step irons with upstand for staggered manhole steps - part 3 : bolted - on step irons
错列人孔直立式阶梯脚扣.第3部分：螺栓连接的阶梯脚扣