The SHIMANO BBES300 bottom bracket, part of the ACERA groupset, is compatible with Shimano cranks with Octalink hubs. Octalink hub cranks are only found in select Shimano models and are not compatible with similar ISIS axles.

Octalink axle type (splined)
bottom bracket shell type: BSA 73mm (right-hand thread on the left side, left-hand thread on the gear side)
total axle length 126 mm
sealed ball bearings
assembly with a splined wrench
actual weight (for a 121 mm long axle) - 306 grams
crank bolts must be purchased separately