BSA (1.37"), 68mm (Road)
For 24mm (Shimano HTⅡ)/SRAM DUB (Road)/30mm (ROTOR 3D+)
3-in-1 core system 
Shimano Standard tool required (44mm, 16 notch)
Bearing size: 30x40x7mm, G5 Ceramic Hybrid bearing for Road bike