FSA H2437B Tapered Fork Head Set  Black GT 1 1/4 " -1 1/8" 

A  semi-integrated part headset for tapered forks and head tubes

• ACB sealed bearings
• TH MR100 1 1/4" Bearing lower 46.8mm
• TH MR155 1 1/8" Bearing cup upper 41.8mm
• Bearing lower (External 46.8mm x 7.3 x 45 degree) Internal 34mm
• Bearing upper External 41.8mm x 7.3 x 45 degree) internal 30.5mm
• 15mm FSA Top Bearing cover 47mm Diameter
• with Split Compression Ring
• Weight 70grams (approx)