i have a listing with all rollers on please check that out 

Theses make light work of any bases or terrain simply add green stuff, clay, foam or anything of your choosing make one roll over. When dry paint the colour you like then dry brush with a lighter colour. 

If you are using them for 25 - 60 mm bases I recommend using 7cm or 9cm for larger bases the 12cm are perfect for terrain pieces.

Size is the length of the roller the scale will be reduced when sized down