Premier Range stair rods come with the following options:

Finials: Balmoral, Chatsworth, Hanover, Lancaster, Windsor, Woburn
Diameter: 12.5mm 
Standard finishes: Antique Brass, Antique Bronze, Polished Brass and Satin Brass.  
Specialised finishes: Black, Brushed Chrome, Chrome, Pewter, Polished Nickel and Satin Nickel.