| Type | Parallel Blade or Opposed Blade Type |
Frame | Galvanized Steel Sheet, Gauge #18 (Gauge #20 for Round) |
| Blades | Formed Galvanized Steel Sheet, Gauge #18 |
| Linkage | Exposed, mounted within the frame. |
| Axles | 1/2″ (12.7 mm) Galvanized Steel Rod |
| Bearing | Self-lubricating Bronze Bushing |
| Control Shaft | 1/2″ (12.7 mm) Round Galvanized Steel |
| Max. Pressure | 3.0 in. w.g. (750 Pa) |
| Max. Temperature | 180°F (83°C) |