Knowles is the originator of balanced armature technology which they apply to their receiver, specialty transducers and hearing aid products. Knowles is also a market-leading manufacturer of MEMS microphones, electret microphones, voice processors and acoustical component accessories.
| Product status | Preferred  | 
		
|---|---|
| Description | Balanced armature receiver  | 
		
| Frequency response curve | Midrange  | 
		
| Configuration | Single  | 
		
| Diameter / length [mm] | 5.09  | 
		
| Width [mm] | 2.8  | 
		
| Thickness [mm] | 2.59  | 
		
| DC resistance [Ohm] | 60  | 
		
| Sensitivity @ 1kHz, 100 mV, in coupler [dB SPL] | 100  | 
		
| Vented | No  | 
		
The FH receiver represents an unprecedented combination of ultra-compact size and high SPL output with efficiencies normally found only in much larger receivers.
| Product status | Preferred  | 
		
|---|---|
| Description | Balanced armature receiver  | 
		
| Frequency response curve | Midrange  | 
		
| Configuration | Single  | 
		
| Diameter / length [mm] | 5.09  | 
		
| Width [mm] | 2.8  | 
		
| Thickness [mm] | 2.59  | 
		
| DC resistance [Ohm] | 60  | 
		
| Sensitivity @ 1kHz, 100 mV, in coupler [dB SPL] | 100  | 
		
| Vented | No  | 
		
The FH receiver represents an unprecedented combination of ultra-compact size and high SPL output with efficiencies normally found only in much larger receivers.
| Product status | Preferred  | 
		
|---|---|
| Description | Balanced armature receiver  | 
		
| Frequency response curve | Midrange  | 
		
| Configuration | Single  | 
		
| Diameter / length [mm] | 5.09  | 
		
| Width [mm] | 2.8  | 
		
| Thickness [mm] | 2.59  | 
		
| DC resistance [Ohm] | 60  | 
		
| Sensitivity @ 1kHz, 100 mV, in coupler [dB SPL] | 100  | 
		
| Vented | No  | 
		
The FH receiver represents an unprecedented combination of ultra-compact size and high SPL output with efficiencies normally found only in much larger receivers.