Phil Wood Stainless Steel Square Taper Bottom Bracket - ISO / CAMPAGNOLOPhil Wood bottom brackets are absolutely legendary. While others claim to offer the ultimate bottom bracket, only Phil Wood has actually done it. This bottom bracket features Phil's 17mm proprietary U. S. produced heat treated stainless steel spindle. This special spindle provides you with maximum durability and an absolute minimum amount of flex. The Phil Wood sealed cartridge bearings have the same seals as those used in submersible pump bearings.