The 536L is in the key of Bb with F attachment and features a lacquered brass body, .525" medium bore, chromed inner slides, nickel silver outer slides, modified open wrap, direct pull trigger, tapered rotor bearing shaft with nylon sockets, 8.1" bell and all comes in a wood frame case. Bb w/F Attachment Lacquered Brass Body .525" Medium Bore Nickel Silver Outer Slide Chromed Inner Slides Modified Open Wrap Mechanical-Link Tapered Rotary Valve 8.1" Bell Wood-Frame Case.