I have found that the Adnams Ghost Ship from my tesco in Scotland has the reusable bungs for the keg. Others that I have tried, such as Hobgoblin and speckled hen have had single use and you need to get a reusable bung to be able to use the keg again. I have also found that getting the single use bungs out blimmin difficult. Had to junk one keg as a result.