The best inverted trigger mechanism ever designed for thermoplastic handles type ROB ALLEN Vecta 1, catalyzing all utilitarian and technical problems with the replacement mechanism . The anatomical chest rest makes it easy and feasible to load multi banded power setups even on shafts with extra rear shark fins- pins or notches. The mechanism’s installation is easy without modifications by using the existing holding pin of the first mechanism. It self-centers 6 cm further back in relation to the classic front mechanism and can accept shafts with extra shark fins- notches. It has an excellent line of site. The trigger, due to its unique design has an unparalleled sensitivity factor due the short route &, best angle of rotation thus the trigger resistance is unaffected under huge loads. As with the other mechanisms of the company, the line release with pushrod design, operates independently of the trigger and the spear preventing the stiff- trigger phenomenon as well as the deformation of the shaft and the deterioration of the shot. All components are thoroughly and evenly sculptured without spikes . The innovative operating system with pushers of the mechanism is patent protected. Any change or modification with respect to the shape, size, dimensions, materials of construction and assembly including a variety of application fields and if it does not include new inventive steps and is not conducive to the technique already known will be considered an aim and aspirations of the present invention.The ideal suggestion to upgrade spearguns with the ROB ALLEN handles Vecta 1.