What is the size of the stair handrail?

Generally speaking, the width of stair tread should not be less than 0.26 m, the height of stair tread should not be greater than 0. 175 m, the height of stair handrail should not be less than 0.9 m, the gap between vertical dry parts of stair handrail should not be greater than 0.1m, and the clear width of stair platform should not be less than the width of stair rest place and should not be less than/kloc-.