Using the reasonably priced INOA hair dye I wondered if any developer would do...but this product line developer has some benefits for hair built in to this! Add to that so far I have dyed my hair Twice and still have lots left makes this a great value. I had been buying hair dye for the online mail subscription service paying a fortune and then shipping on top of that despite doubling orders which should have worked. That product faded so quickly unlike INOA which lasts even with red hair. Plus I like that as long as I do not mix this developer with the dye I can add a little more red in the summer or go a little more darker in the winter just by adding a complimentary color to go with the base and developer..saving the rest of the product for the next time needed..The bottle goes a long, long way and gives me the power to find the subtle shade differences that make me so happy I am a red head.