Ultra-Core™ and Dura-Core Difference™
Ultra-Core 
| Core Depth | Rows of Tubes | Centers |
| 1 1/2" | 2 | 1/2" tubes on 3/8" centers |
| 2" | 3 | 1/2" tubes on 3/8" centers |
| 2 5/8" | 4 | 1/2" tubes on 3/8" centers |
| 3 3/8" | 5 | 1/2" tubes on 3/8" centers |
* Available with smooth or dimpled tubes
Econo-Core 
| Core Depth | Rows of Tubes | Centers |
| 1.296" | 2 | 1/2" tubes on 9/16" centers |
| 1.972" | 3 | 1/2" tubes on 9/16" centers |
| 2.658" | 4 | 1/2" tubes on 9/16" centers |
| 3 3/8" | 5 | 1/2" tubes on 9/16" centers |
* Available with smooth or dimpled tubes
Dura-Core H 
| Core Depth | Rows of Tubes | Centers |
| 1 7/8" | 2 | 1/2" tubes on 1/2" centers |
| 2 1/8" | 3 | 1/2" tubes on 1/2" centers |
| 2 13/16" | 4 | 1/2" tubes on 1/2" centers |
| 3 1/2" | 5 | 1/2" tubes on 1/2" centers |
| 4 3/16" | 6 | 1/2" tubes on 1/2" centers |
| 4 7/8" | 7 | 1/2" tubes on 1/2" centers |
| 5 9/16" | 8 | 1/2" tubes on 1/2" centers |
* Available with smooth or dimpled tubes
* Louvered or non louvered fin
* Louvered or non louvered fin
Dura-Core N 
| Core Depth | Rows of Tubes | Centers |
| 1 7/8" | 3 | 1/2" tubes on 5/8" centers |
| 2 3/8" | 4 | 1/2" tubes on 5/8" centers |
| 3" | 5 | 1/2" tubes on 5/8" centers |
| 3 7/16" | 6 | 1/2" tubes on 5/8" centers |
| 4" | 7 | 1/2" tubes on 5/8" centers |
| 4 1/2" | 8 | 1/2" tubes on 5/8" centers |
* Available with smooth or dimpled tubes
* Louvered or non louvered fin
* Louvered or non louvered fin
Dura-Core I 
| Core Depth | Rows of Tubes | Centers |
| 1 7/8" | 2 | 1/2" tubes on 1/2" centers |
| 2 1/8" | 3 | 1/2" tubes on 1/2" centers |
| 2 13/16" | 4 | 1/2" tubes on 1/2" centers |
| 3 1/2" | 5 | 1/2" tubes on 1/2" centers |
| 4 3/16" | 6 | 1/2" tubes on 1/2" centers |
| 4 7/8" | 7 | 1/2" tubes on 1/2" centers |
| 5 9/16" | 8 | 1/2" tubes on 1/2" centers |
* Available with smooth or dimpled tubes
* Louvered or non louvered fin
* Louvered or non louvered fin
