| Legacy | Series III | Notes |
 |  | 1500A, 1500B Counter Stations
- New 1500B counter stations may be added to an existing legacy system in most cases. Some older systems may require a firmware update.
|
 |  | 1502B 2-way Video Monitor
- Legacy counter stations are compatible with new 1502B video monitors, but the third screw should not be used.
|
 |  | 1503B Handset
- The handset option is not compatible; if you are replacing a 1500AH with a new counter station, you cannot use the old handset. Likewise, the new 1503B and 1503BH handsets cannot be used with legacy counter stations.
|
 |  | 1520 Lane Stations
- Series III lane stations (1520B) are functionally equivalent to legacy 1520 models, ready for drop-in replacement. Note: legacy 1520 does not have grounded jacks.
|
Not Compatible |  | 1522B Dual Lane Station
- The dual lane station (1522B) is NOT COMPATIBLE with 1580 series - DO NOT CONNECT 1522B with 1580 series equipment, damage will occur. 1522B may be used with a legacy 1500A counter station.
|
 |  | 1515B and 1516B AV System HUB Cards
- 1515B and 1516B hub cards may directly replace legacy hub cards in 1510 style card cage hub.
|
 | 
| 1509B Mini Audio Hub
- The 1509B may directly replace a legacy Audio Mini Hub.
|
 | | 1509BV Mini Audio-Video Hub
- The 1509BV may be used to replace a 1510 hub if only two counter stations are required; however, if advertising messages on hold are required, a new 1510 should be installed.
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