Threetop Company (Threetop Optical Electric Technology Co., Ltd.) specialized in studying , desiging , manufacturing and selling laser modules .Our company aim at the oversea market of laser and photoelectron especially direct against the semiconductor laser application especially. We have manufactured Hundred of produces such as Red laser modules, Green laser modules, Infrared laser modules, Beam expander laser modules (including Point, Line and Cross lasers). The products are widely used in mapping apparatus, industrial direction, laser distance finders, building put line, laser levels, medical treatment, military affairs, test teaching, light of stage, laser point to appearance field.