Beginning in 1976, they came up with various designs of foot-operated pumps which, because they only used one leg, were not comfortable and had low output. The last design before the treadle pump was a “Y-pump”, having two cylinders welded together in a Y shape, and a hand-driven rocking frame so the hands could help the foot. The plungers were also of a special and more efficient design, which were subsequently adopted by the handpump industry in Bangladesh and India. The improvements started to gain interest for the pump. With the development of the treadle pump, using components of the Y pump but having the use of both legs, there was immediate interest and demand.