BlogHide Resteemsxonline (25)in skp • 6 years agoButterfly valveButterfly valve 3 " is built with a SketchUp program which is available for download for free. Download at the link below.xonline (25)in two-way • 6 years agoConnecting the 2-way switchConnecting the 2-way switch Connecting the 2-way switch to control the closure The opening of the lamp inside the house More convenient for users in the case of a 2-storey house. This type of…