Abstract: Unique constructional improvements in constructions involved in pumping. The invention is particularly adapted in deep well pumps which may be water or oil pumps or otherwise. The invention greatly reduces the mass of moving parts thereby proportionately reducing the energy required for pumping operations. Dual pistons are utilized which reciprocate oppositely, being connected by a cable passing over a pulley. Heavy sucker rods and pistons are eliminated. The pistons are light-weight with light-weight bellows-type seals. The pistons are activated by way of cables rather than sucker rods. Further gains are realized by minimizing the size of the piping utilized. This end is realized by way of an offset staggered relationship of the operating pistons in a smaller pipe or by way of plural pistons arranged in vertical array or assembly.