This is a set of ALL band instruments' first 5 notes (Concert Bb, C, D, Eb, F). After cutting and folding, each flash card is 5.5 x 4.25. These can be printed on plain computer paper (once folded, the answer does not show through) and are perfect to copy and give to each student for their personal home practice.
I used to use index cards and have each student make their own flash cards. While that does have its merit, these are simple and less time consuming.
The pdf is large since it includes all instruments. However, you can just print off the instruments you need.