Mouthpieces

Trombone
Grades 5-7: Bach 6 1/2AL (small shank)
Grades 8-12: Bach 5G, Hammond 12ML or 11ML (small or large shank, depending on instrument)

Euphonium
Grades 5-7: Bach 6 1/2AL (small shank)
Grades 8-12: Schilke 51D or 52, Hammond 11L or 11XL (small or large shank, depending on instrument)

Tuba (BBb or CC)
Grades 5-8: Bach 18
Grades 9-12: Perantucci PT-50 or Bach 7