The SRAM PC-991 is nearly identical in design to the PC-991 Hollowpin. The hollow pins have been replaced with chrome-hardened solid pins, which is reflected in the slightly heavier weight and the lower price. Otherwise the link design is the same. Comes with a gold-colored PowerLink connector to make assembly and disassembly easy, a big plus for people who need to devote regular attention to their chains. It will work with all other 8 and 9 speed cassettes.