Conditioner bar by The Natural Spa (we sell them).
How do solid conditioner bars work?

I've been using them for months now and my hair has never felt better. After using the shampoo bar, rinse out all of the shampoo. Smooth the conditioner bar over your hair, starting at the top and moving out to the end. Leave for a minute or two and rinse out.

N.B. make sure that you let the bar dry between washes and it will last for ages.