A switched coupler type digital phase shifter using a quadrature generator is disclosed. The inner space is sealed by a primary sealing element against splash water and other detrimental influences. A thickness of a polishing pad can be calculated. The object of the present invention is to provide contestants with a way of mitigating the inherent risk of being eliminated from most roping competitions after one, two, or a short amount of runs and having to bear the complete loss of entry fees, travel, board and other incidental expenses.