There are many variations in hob design available. From one to four burners, with or without a grill and with the addition of spark igniters. All modern units have flame failure devices and the most popular units have independent glass lids. Apart from a few diesel and 240v electric units, most are gas. Jetted at 30 mb they can except Butane ( 28 mb ) , Propane ( 30 mb ) or camping gaz ( 30 mb )