Kitufe cha usalama cha aina ya Mbunge ni chombo cha lazima cha kushikilia kola za kuchimba visima, mabomba ya pamoja na mabomba madogo ya bega. Kwa kuongeza au kupunguza tu kiungo cha mnyororo, mahitaji mbalimbali ya kamba ya bomba yanaweza kutumika. Bidhaa zimeundwa na kutengenezwa kulingana na mahitaji ya API Spec 7K.
| Mfano | Kipenyo cha bomba kinachotumika (ndani) | Idadi ya viungo |
| Mbunge-S | 27/8-41/8 | 7 |
| 4-5 | 8 | |
| Mbunge-R | 41/2-55/8 | 7 |
| 51/2-7 | 8 | |
| 63/4-81/4 | 9 | |
| 8-91/4 | 10 | |
| 91/4-101/2 | 11 | |
| Mbunge-M | 101/2-111/2 | 12 |
| 111/2-121/2 | 13 | |
| 121/2-135/8 | 14 | |
| 135/8-143/4 | 15 | |
| 143/4-157/8 | 16 | |
| Mbunge-L | 157/8-17 | 17 |
| 17-181/2 | 18 | |
| 181/8-193/8 | 19 | |
| Mbunge-XL | 193/8-203/8 | 19 |
| 203/8-211/2 | 20 | |
| 21-225/8 | 21 | |
| 225/8-223/4 | 22 | |
| 233/4-247/8 | 23 | |
| 247/8-26 | 24 | |
| 26-271/8 | 25 | |
| 293/8-301/2 | 28 |