Are water heater anode rods universal?

In most cases, water heater anode rods are universal. The only exceptions are :

Buderus : They use another type of threading to install the magnesium anode.

Bradford White : Some model have the anode is built into the hot water outlet.

All other water heater brands use a regular magnesium anode with 3/4 ” NPT threads.

Corro-Protec anodes are designed to fit any hot water tank on the market. You can see all models on the following link : Residential and Commercial Water Heater Anode.