WFC - Very hard. Fast cutting polishing mop. Good for making rigid abrasive scurfs. 6G/S - Hard. Fast cutting mop where more flexibility is required. Makes a good abrasive scurf with some flexibility. B - Medium/hard. Good cutting mop for non-ferrous metals. Flexible. Makes a good scurf - more flexible than 6G, especially in narrower sizes. G - Medium, general purpose finishing mop with finishing compounds. Good for rougeing where little cut is required. WDR - Soft. A raised one-sided lint finish mop, excellent for silver rouge finishing. Brush free finish if used at correct peripheral speed. WHR - Soft Swansdown. An all round finishing mop for all metals. A must for precious metals. Reflex - Soft rougeing mop for finishing gold and especially silver - no rouge burn into silver.