18 inch brush roller assembly. 
Uses 2 belts and the V belt goes around the roller. 
Genuine Hoover replacement part 48416036. 
18 inch agitator assembly fits select Hoover commercial vacuum models: 
- Conquest - U7071, U7071-040 
- Conquest - U7071-070, U7071-080 
- Conquest 18 - C1800, C1810 
- Conquest 18 - C1810010, C1810020 
- Conquest 18 - C1820 
- Conquest 18 - CH1800010, CH1810010 
- Industrial - C1119, C1119-080 
- Professional - C1805, C1815