Bosch Ariston GL Kit for GL2.5 and GL4 Contains the sacrificial anode rod, old-style heating element without temperature sensor (see picture) and gasket/screws Can only be used for the Ariston GL2.5, Ariston GL4, Ariston Pro Ti GL2.5Ti, and Ariston Pro Ti GL4Ti mini-tank water heaters CANNOT be used for the Ariston GL6+, Ariston Pro Ti GL8Ti, Ariston Pro Ti GL8TiS or Bosch Tronic 3000T ES8 mini-tank water heaters CANNOT be used for the new "S" Series Ariston heaters (i.e., the Ariston GL2.5S, Ariston GL4S, Ariston Pro Ti GL2.5TiS, Ariston Pro Ti GL4TiS, Bosch Tronic ES2.5 or Bosch Tronic ES4)