Material: The bolt is crafted from high-grade chromoly (chromium-molybdenum) steel, known for its exceptional strength and resistance to shearing, fatigue, and corrosion. -Compatibility: It is designed exclusively for square taper bottom brackets, which were common on many older or budget-friendly bikes. It is not compatible with ISIS or other bottom bracket types. -Thread Size: The bolt features an M8 thread size. -Drive Type: Installation and removal require an 8mm Allen (hex) key. -Protective Cap: The bolt includes a plastic cap to help keep dirt and moisture out of the bottom bracket spindle area. -Durability: According to descriptions from retailers like 365 Cycles, the robust chromoly construction ensures a long-lasting and secure connection, improving drivetrain stability.