SRAM Rival OG 1070 10-Speed OpenGlide Road Bicycle Cassette 2008 SRAM OG-1070 10-speed cassette 11-25t FW6203 OG stands for Open Glide, where each cog features a cut tooth to aid in shifting. Largest 3 cogs are attached to an aluminum spider Ships in USA for $9.50 Priority Mail SRAM 1070 cassettes are Shimano 10-speed compatible. Do not fit on Dura-Ace 10-speed hubs.