The Nine Volt Flash Tube for Profoto Pro Head is a 2400Ws spare or replacement.\r\n\r\nThe flash tube is user-replaceable.\r\n\r\nIt can withstand the heat from a 500W modeling lamp.\r\n\r\nIt's compatible with the Profoto ProHead Plus, Pro-B Plus, Pro-Head, Pro-6, Pro-7,\r\nPro-B, and Pro-7B flash heads.