A 7th flat five chord is created by flattening the 5th degree of any dominant 7th chord. For example, a C7b5 chord contains the notes C, E, Gb and Bb (1, 3, b5 and b7). Here are some common open 7th flat five chord shapes.
C7b5
Db7b5
D7b5
Eb7b5
E7b5
F7b5
F#7b5
G7b5
Ab7b5
A7b5
Bb7b5
B7b5