Semi-automatic safety system that disengages by placing pressure and pushing forward with the thumb on the surface situated on the external part of the “rotating lace” and is engaged by manually placing the lace on the weapon hammer. It is possible to block the system by sliding a button which, when moved forward, prevents the lace from sliding downward. the system it can also be adjusted on the front with three slots for to carry the lace near or distant to the weapon hammer.