Most of the strong light flashlights are cup-shaped focusing, and most of them are not focusing. The focusing is basically lens-type. The focusing methods are divided into common stretching focusing and screwing focusing. The latter is more reliable. But no matter which method, the overall reliability is reduced due to its movable structure, so high-reliability military and police flashlights basically do not need to focus. The stretch type has the lowest reliability. It is also the most vulnerable. The illumination effect is also the best of the light cup type, because there is a central focused beam to strengthen the illumination of the target, and the floodlight area around the beam forms a focused and scoped illumination effect, which is in line with people’s visual habits. Is the best lighting mode.