A-Series
600mm (5cyl I6 V10 and V12) 400mm (3cyl 4cyl V6 and V8) Bore Size 17.2mm Top of Rail has a Rounded Profile Raw alloy finish
A-Series Large Bore
600mm (5cyl I6 V10 and V12) 400mm (3cyl 4cyl V6 and V8) Bore Size 20mm Top of Rail has a Rounded Profile Raw alloy finish
C-Series
600mm (5cyl I6 V10 and V12) 400mm (3cyl 4cyl V6 and V8) Bore Size 16mm Top of Rail has a Square Profile Raw alloy finish