Thumb F(sharp) with two
Rollers on both sides of the thumb F(sharp) key are adjacent to both the low E key and the thumb G(sharp) key.
Catalog Number: 76
Available On: 601, 660, 201, II, III, & IV
Standard Included On: 101 & I
Conflicts With: Thumb F(sharp) Roller (75)
Required Addition: Thumb A(flat) Roller (77)