NGK 1249 Metal 11V 5.5A 0.6 Ohm Diesel Engine Heater Glow Plug Y-705RS. This listing is for ONE NGK glow plug; please select the quantity you require prior to completing your purchase. From the worlds No.1 spark plug manufacturer you’d expect nothing but the best from their glow plugs too; and you’d be right. NGK have been relentlessly developing engine pre-heating technology since the early 1960s and the inbuilt advanced technology ensures that automotive engineers can get the most out of their engine designs and help them meet the increasing demands for fuel efficiency and reduced emissions.