The black safety flanges are designed to increase the safety of centered buffs. Unlike the custom centerless flanges these are designed to fit over the centerplate of the buff. These are a safer alternative than just using a buff with welded centers. These are designed to be used with any grinder under 6,000 rpm with a 5/8" arbor hole sito web dell'azienda.
If you are looking for even more protection for your buffs look into the insertable flanges. The custom centerplates are only for the centerless buffs.