3C- Acoustics
3C10.10 Model of Ear Q-1L Maryland
3C20.10 Range of Hearing Q-1R NCSU Maryland
3C20.30 Siren Disc Q-1C
3C30.22 Sound Level Meter Q-1C Maryland
3C55.70 Microphone and Scope 10-5R Maryland
3C55.72 Fork and Box on Scope Q-3C