Balcony Guardrail is the beautification and protection of the outer edge of the balcony. The alloy pipe is welded or assembled. The common low window sill is about 0.5 meters away from the ground. If the 0.4 m guardrail or fence is added close to the inner wall, the protective measures required by the specification must be met. If the window sill is too large, such as a bay window, the child often stands on the window sill and the user must stand on the window sill to open the window. At this time, the height of the guard rail attached to the window sill should be 0.9 meters.