It's a Blu-Ray world these days and for those of you still rocking the crank equivalent of VHS, this Octalink bottom bracket is on the case to help keep your otherwise perfectly good bike on the road.
Octalink bottom brackets are compatible across the board so even though this is a 105 bottom bracket, it works just fine with Ultegra and Dura Ace plus any other brand of crankset utilizing the Octalink design.
This particular bottom bracket is English threaded and measures 68 x 109.5mm, which is the spindle length to fit double cranksets. This bottom bracket is not compatible with triple set ups.
Although the description doesn't mention it, this is actually a V1 Octalink bottom bracket (picture is outdated). The original 105 was a V2 Octalink, but the 5500 edition eventually changed to V1 Octalink - because this 5500 V1 Octalink is the only V1 Octalink BB still manufactured by Shimano, thus is intended to support users still running 6600/7700 Ultegra & Dura-Ace cranksets. If you are like me, chances are you still have a spare bike using an Octalink crankset. It's great news to know these bottom brackets are still [for now] being manufactured. Chances are if you are also running one, you know the longevity of these BB's is hit-or-miss (exposure to rainy rides significantly decrease lifespan). Unfortunately they are not rebuildable, so replacement is a must. I have been averaging anywhere from 3,000-5,000 miles on these BB's before they develop 'play' in the spindle/bearing assembly and require play. My advice would be stock-up on these while they're still being made! I'm rating it 4/5 and not perfect 5/5 because they are a little bit more pricey than Hollowtech II BB's and can't be rebuilt.