The reduced diameter (16.6 mm) allows the V3 Power Unit to be mounted within the seatpost, by using one of the two available adapters (for ø 27,2 and ø 31,6 mm), thus reducing assembly time. Specification: For 27.2mm and ø 31.6mm posts. 16.6mm. V3 Compatible.
Best Price: £4.50 from Merlin Cycles