Double gas cylinder trolley It is made out of MS -“L” Angle support (50 x 50 x 3mm thick) Provide 6” x 2” 10” x 2” type wheels for smooth moving. It is a Four wheel Type. a leading manufacturer and distribution of climbing equipment. All SEW Engineering products are designed and manufactured to the same rigorous quality standards and with a common goal of building the safest Aluminium ladders possible.