**no manual/packaging, just as shown 2pcs Replacement Salt System Cartridge Spa Salt Cartridge - Spa Salt Cartridge for Home Spas and Spa Clubs (2 Pack) [Economical]:Our Salt Cartridges Do Not Require Frequent Replacement Of Cartridges, effectively reduce water hardness, reduce the formation of scale and sediment [Spa Comfort] Our Salt System Cartridges Provide Better Comfort For Your Spa Time And Better Relaxation While Enjoying Your Spa After A Busy Day!The Chlorine Content Produced Is Stable And Mild, Suitable For Most People. [Easy Installation]: First Turn Off The Power, Then Check The Ph Value Of The Water With Test Paper, Then Remove The Old Cartridge, Next Install The New Cartridge, And Finally Set The Control Panel To Start