The J.A. Custom Discovery 48 Advanced has great response and tone. Upgraded with a new 2 part slide system the Discovery is one of the best 12 hole chromatic harmonicas on the market. The 2 part slide mechanism, gives the harmonica a much better slide action, but it also give the player better response and dynamics. The valves are modified for a much smoother action, and it features expert reed work, including a distinct embossing method.