Ndoo ya tope hutumika kukwaza uzi wa kuchimba visima, kuzuia kuchafua jukwaa kwa kumwaga matope kwa sababu ya kuzuia wakati wa kutenganisha zana za kuchimba visima, kuchakata maji ya kuchimba visima, ina faida za usalama na urahisi, kuweka usafishaji wa jukwaa na kuokoa matope, Wakati wa safari na kutenganisha zana za kuchimba visima, ndoo ya matope inaweza kuzuia upotezaji wa kazi ya lazima na upotevu wa lazima. salama na safi zaidi.
| Mfano | OD | OAL | Ukubwa wa Bomba la Drll |
| mmn (inchi) | mm (ft) | inchi | |
| FH2-3/8 |
273(10-3/4) |
1826 (6) |
2-3/8 |
| FH2-7/8 | 2-7/8 | ||
| FH3-1/8 | 3-1/8 |
||
| FH3-1/2 | 3-1/2 |
||
| FH4 | 4 |
||
| FH4-1/2 | 4-1/2 |
||
| FH4-3/4 | 4-3/4 |
||
| FH5 | 5 |
||
| FHS-1/2 | 5-1/2 |
||
| FH5-7/8 | 5-7/8 |
||
| FH6-1/2 | 6-1/2 |
||
| FH6-5/8 | 6-5/8 |