1+ Brake booster  
2+ Brake master cylinder  
3+ Reservoir  
4+ Reservoir cap  
5+ Seal  
6+ Securing pin  
7+ Seal  
8+ Locking nut  
9+ Gasket  
10+ Locking nut  
11+ Vacuum pipe  
12+ Valve seal  

The part numbers in the assembly image below relate to the product number in the table. Clicking on the part number will open up the relevant part details.