Special Copper rivets and rails. The B17 is an all leather cover with rivets plus tension adjuster. When broken in Brooks saddles are considered by many to be the most comfortable on the market. The Standard width 6 3/4 is ideal for commuting, long distance trekking and general purpose riding. Copper Plated Steel rails. 518g. weights vary slightly, due to cover thickness . Classic B17 is an all leather cover with brass rivets plus tension adjuster When broken in Brooks saddles are considered by many to be the most comfortable on the market The Standard width 6 3/4 is ideal for commuting, long distance trekking and general purpose rides Special Copper rivets and rails 518g. weights vary slightly, due to cover thickness