Behind the saddle bottle cage mount for saddle ISM PN 1.0. Don't know if it would work with any other saddles. It mounts to the saddle rails using 4 M5 screws and hexagonal nuts. Printed using PETG fillament. Tested with fully filled 750ml bottle, nothing broke so far, even on more bumpy roads. Bottle cage final position depends on your bottle cage design and mounting holes. Mine is mounted as much to the front as possible for maximizing aero gains.

Hardware needed:

• 4 M5 screws 30mm example: https://www.amazon.pl/dp/B0D5QVSQLB?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1
• 4 M5 hexagonal nuts example: https://www.amazon.pl/dp/B0BJZM3B5R?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1
• 2 M5 threaded inserts 15mm example: https://www.amazon.pl/dp/B0FBRF247K?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1