The slx m677 hollowtech ii 10 speed mtb 3824 chainset from shimano is a tough and aggressive all mountain chainset that is also lightweight and excellent value for money it features hollow forged crank arms which are both lightweight and rigid whilst keeping the incredibly strength and durability the hollowtech ii integrated bottom bracket design uses a wide bearing placement with a large axle diameter for increased stiffness efficiency and added durability the chainrings are hg x 10 speed