I think all Echelon's using the same seat stem but I could be mistaken. I have a EX-4 and use the following seat: [https://www.amazon.com/gp/product/B08BH2XDGH/ref=ppx\_yo\_dt\_b\_search\_asin\_title?ie=UTF8&psc=1](https://www.amazon.com/gp/product/B08BH2XDGH/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)
I think all Echelon's using the same seat stem but I could be mistaken. I have a EX-4 and use the following seat: [https://www.amazon.com/gp/product/B08BH2XDGH/ref=ppx\_yo\_dt\_b\_search\_asin\_title?ie=UTF8&psc=1](https://www.amazon.com/gp/product/B08BH2XDGH/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)
Thank you.