The Cervelo Internal Di2 Mount for S5 is a replacement Di2 battery mount for internally mounting a Shimano Di2 battery within an S5 downtube. The mount is only compatible with Cervelo S5 seatposts for 2014 onwards models.

Shimano Road free hub body
Freehub Body: HG L (Shimano 11/12s Road)
Suitable for all CADEX rear wheels
Incl. QR end caps