This is our MRCE2CAPK6 which uses aluminum anode material. For zinc please review MRCE2CZPK6. Offered is a 1.5" 6 pack of full anode assemblies which includes the brass holder and anode. This is the easiest way to replace the anode for your heat exchanger. This is for a 1/2" NPT thread size and will be a drop in replacement for a heat exchanger that has that size anode fitting. These parts will replace any 1.5" E2C product or you can cut it to length if it is shorter. Anodes may not be returned so be careful when ordering.