A silver Phillips-head or slotted-head screwdriver with a colorful handle. Most platforms show a red handle, though Apple's design has a green handle. Used to represent construction, building, carpentry, renovation, or tools in general.
Sometimes used in phrases with 'screw' in them like screw you or have a screw loose. Can also be used in sexual contexts due to the informal meaning of 'screw': "to have sex."