It is the most needed tuning pack - better then to buy the 7harps pack with E, Bb+F tunning used not frequently. Probably once. Not still again!
BUT WHAT I CANNOT A LONG YEARS UNDERSTAND, WHY EV´RYBODY (feat. HOHNER and others) DOESNT ADD THE ONE MORE HARP of a "D" tunning!! SHAME!
CONCLUSION - buy, tear off brrrrrutally with a heawwwy-methalll GRRROOOOWWWL the inner partiitons (not a velvet padding of course), then buy separately D harp, add and - enjoy most of the songs !!!
About a tone etc. pls. see comment of 7harps bundle...