Thumb A(flat)/B(flat) Trill Key
Added raised above the right thumb F(sharp) and G(sharp) spatulas. Alternate spatula positions could include behind the thumb G(sharp) spatula, in place of the thumb G(sharp) spatula, or above the thumb B(flat) spatula.
Catalog Number: 11
Available On: 601, 660, 101, 201, I, II, III, & IV
Conflicts With: Articulated A(flat)/B(flat) Trill, with clutch (12); Articulated Ab/B(flat) Trill, without clutch (13)