For bottle size, add to part number:
-00 System less bottle
-05 System with 5lb bottle
-10 System with 10 lb bottle
-12 System with 12lb (Composite) bottle
-15 System with 15lb bottle
MainLine EFI Nitrous Systems

(Click images for more information)

MainLine EFI Nitrous System
PN: ML2000
Horsepower: 50-150whp

MainLine SportComp EFI Direct Port
Nitrous System
PN: ML5000
Horsepower: 100-500whp