| Mfr. Part No. | Description | 
| 141B | Nominal Impedance (Ohms), Primary, 200 K | 
| 141D | Nominal Impedance (Ohms), Primary, 3000 ct | 
| 141F | Nominal Impedance (Ohms), Primary, 25 K | 
| 141H | Nominal Impedance (Ohms), Primary, 600 ct | 
| 141M | Nominal Impedance (Ohms), Primary, 30K | 
| 141P | Nominal Impedance (Ohms), Primary, 1200 ct |