| Mfr. Part No. | Description |
| HT24100 | 24 VAC, 100 VA, current 4.0 A; Class 2 open-frame with thermal cut-out. |
| HT24200 | 24 VAC, 200 VA, current 8.0 A; Open-frame with thermal cut-out. |
| HT28100 | 28 VAC, 100 VA, current 3.57 A; Class 2 open-frame with thermal cut-out. |
| HT28175 | 28 VAC, 175 VA, current 6.25 A; Open-frame with thermal cut-out. |