General Description for knobs as following:

Material:  Most of our knobs are made of zinc alloy.
Size:         Diameter of mounting hole 4.0mm with 8.0mm depth standard. And some 
                 items are with special specifications, please note their details.
Finishes: Available for various plating finishing as following:

• CP-chrome plated
• DC-dull chrome plated
• GP-gold plated
• BP-brass plated
• AC-antique copper plated
• AR-copper plated
• SP-silver plated

• PC-pearl chrome plated
• SC-satin chrome plated
• SG-satin gold plated
• AB-antique brass plated
• AE-antique English plated
• GN-black gun plated