ZIPP SL Speed Di2 Internal Battery Mount for Seat Post

The ZIPP battery mount is an insert which provides the mounting of Shimano Di2 batteries within the inside of a SL Speed seatpost. 2 versions for 27.2 mm or 31.6 mm are available.
Material: plastics
Weight supplement: version for 27.2 mm | manufacturer's specs)
approx. 19 grams (version for 31.6 mm | manufacturer's specs