| Features | Standard | Available Option |
| Frame | Cast iron | Fabricated steel |
| Bearing Housings | Cast iron or Fabricated steel | N/A |
| Main Terminal Box | Cast iron | Large Fabricated steel |
| Auxiliary Boxes | Cast iron | NEMA 4X |
| Shaft | AISI 1045 for N315LL-N355LL AISI 1035 for N400LL | AISI 4140 |
| Rotor | Die cast aluminum for N315LL & most N355LS\LL frames, fabricated copper for N400LL | Fabricated copper for N315LL-N355LL frames |
| Lamination Material | High grade low loss silicon steel | N/A |
| External Cooling Fan | Aluminum or Fabricated steel | Copper available |
| Fan Cover | Fabricated steel | N/A |
| Insulation | Class F random wound | N/A |
| Paint \ Color | PU \ Wooden Grey(Munsell 7.5Y 8.9/0.4) | Special paint system \ Other colors |
| Bearing Type | N.D.E Angular or Spherical bearing, N.E. Ball bearing | High thrust plate bearing |
| Vibration | 0.12 IPS or as defined by NEMA | Special balance |
