The "ME-" indicates our SKU part number which has the form "ME-"|MPN where MPN is the Manufacturer's Part Number. The ME stands for McBrady-McMahon Engineering. You will get better product search results using with our SKU. Parts numbers usually end with a "-P", Stainless steel products "SS", "M" means spark resistant, a prefix of "CP" indicates a Control Panel, products that end with "115" are 115V and "230" are 230V systems. The GEK prefix to a part number means Guard Enclosure Kit for customer installs. An "E#" in the part number indicates explosion proof. Similarly, GEO means Guard Enclosure Option installed at the factory.