The Box Vector M30-P cranks feature a 2-pc design with hollow forged aluminum arms, integrated 4-bolt 104mm spider gear, a 30mm hollow 7075 aluminum spindle to maximize strength and rigidity Praxis 30mm external Euro BB with CNC machined 6061-T6 aluminum cups and oversized precision sealed bearings for smooth operation M30 BB installation tool included 180mm Euro BLK 104mm 4-bolt 771g 1UPC/EAN/GTIN: 616043824802