The X-mas Tree Cap is mounted on top of the X-mas Tree and provides access to the tree plug and hammer hut. Standard API-UP tubing lift thread is provided in the body.
The plug has the provision for mounting a pressure gauge to measure well pressure.
| Type | Lower Connection | Bore | Lift Thread |
| B-15-A | 2-1/16†2000 | 2-1/16†| 2-3/8†EUE |
| 2-1/16†5000 | 2-1/16†| 2-3/8†EUE | |
| 2-9/16†2000 | 2-9/16†| 2-7/8†EUE | |
| 2-9/16†5000 | 2-9/16†| 2-7/8†EUE | |
| 3-1/8†3000 | 3-1/16†| 3-1/2†EUE | |
| 3-1/8†5000 | 3-1/16†| 3-1/2†EUE | |
| B-11-AO | 2-1/16†10000 | 2-1/16†| 2-3/8†EUE |
| 2-9/16†10000 | 2-9/16†| 2-7/8†EUE | |
| 3-1/16†10000 | 3-1/16†| 3-1/2†EUE |
AA-EE, L-U, PSL 2& 3, PR2