100% European Birch shells BD shells: 10 ply, 10 mm SD, TT & FT shells: 7 ply, 7 mm Tunesafe system - maximum tuning stability CLTF tension-free shell forming process OSM slightly narrowed outside shell measurements 45° bearing edges Sound Sustainer mounting system on all tom toms and floor tom leg brackets Dual Glide snare strainer mechanism 4 different matte lacquer finishes Bass drum hoops with different finishes (Natural Beech and Walnut) All bass drums without mount Remo USA Ambassador Coated batter heads and Ambassador Clear resonant heads (snare drum, tom toms & floor toms) Remo USA Powerstroke P3 Clear batter head Powerstroke P3 Fiberskyn resonant head with “off-set” SONOR logo (bass drums)