We recommend a 9" airway buffing wheel size for most—it offers a great balance of maneuverability and life of the buffing wheel. For greater detail work, consider an 8" buffing wheel. The 10" and 12" (custom size) are often so large as to only to be used by professionals on large flat work, such as a fuel tanker. Businesses, professionals, and skilled users may find that 10" Airway Buffing Wheels are ideal for them because of the longer life of the wheel. Some users purchase 10" Airway Buffs with the intention of wearing them down to 8" or 9" to use for their detailed work, as opposed to buying multiple sizes. ALUMINUM POLISHING: STEP 1 (CUT): PAIR ORANGE AIRWAY W/ TRIPOLI (BROWN) BAR. STEP 2 (COLOR): PAIR YELLOW AIRWAY W/ GREEN ROUGE BAR. STEP 3 (SHOW SHINE): DOMET FLANNEL (WHITE) AIRWAY PAIRED WITH EITHER PURPLE ROUGE BAR OR BLUE ROUGE BAR. STAINLESS POLISHING: STEP 1 (CUT): RED AIRWAY PAIRED WITH BLACK MAGIC ROUGE BAR. STEP 2 (COLOR): PINK AIRWAY PAIRED W/ YELLOW ROUGE BAR. STEP 3 (SHOW SHINE): DOMET FLANNEL AIRWAY PAIRED WITH PURPLE ROUGE BAR OR BLUE ROUGE BAR.