SHIMANO® DI2 seatpost battery collar.

With griding paper, alcohol wipe, glue.

MATERIAL : AL6061-T6
SPEC : ADP-DI2-27.2 for seatpost I.D. Ø22.2mm
            ADP-DI2-31.6 for seatpost I.D. Ø27.2mm
            Seatpost I.D. must be round
            ADP-DI2 O.D. Customer design available
WEIGHT : 16g/pcs (For Ø27.2mm)
                  28.5g/pcs (For Ø31.6mm)