This cylinder is now either what remains of the NOS of Lucas Girling or its successor TRW who took over Girling. You will get which ever is available at the time of ordering, sold indivdually not as pairs 
 
Part Name: Rear Wheel Cylinder, 7/8" Diameter, Genuine Original Lucas Girling
AlfaStop Product Code: 1BRR101
Original Alfa Romeo Part No: 1740.33.703
Model: Guilia 101 Series, Giulietta 750 & 101
Quantity Per Car: 2