| Option | Description |
|---|---|
| 001 | Medium-stability timebase |
| 010 | High-stability timebase |
| 015 | 1.5 GHz RF input Ch 2 for 53181A only |
| 030 | 3 GHz RF input Ch 3 |
| 050 | 5 GHz RF input with type N connector Ch 3 |
| 060 | Rear-panel connectors |
| 061 | Moves 3.0 GHz Channel 3 |
| 062 | Moves 5.0 GHz (Option 050) or 12.4 GHz |
| 12 | Ultra-high stability timebase (53132A only) |
| 124 | 12.4 GHz RF input with type N connector Ch 3 |