The MAD DOG multiple expansion foam nozzle offers a rugged versatility and performance not found in any other nozzle. With a twist of the wrist the MAD DOG produces low expansion foam (ratio approx. 12:1) with excellent stream projection or medium expansion foam (ratio approx. 30:1) with incredible production. Quality of water and foam concentrate greatly affect expansion rates. After thousands of tests, demos, and field use the Mad Dog usually produces the best quality foam with Phos-Chek WD881 concentrate.