I bought my first Biktrix bike after my mom passed away. A Stunner LT 5 which has served me quite well. I opted to upgrade the saddle because I wanted this to be a nicer ebike than my DIY home builds. The Promend seat did not come with a seatpost, so I used the original saddle for a few weeks until I swapped for the Promend. At first, it was great. Comfy and the springs help you pedal harder with less pain. After just a few months though, I started to have problems. The seat wasn't sitting right on the holder. I tried to adjust it and reposition it on the seatpost. But upon further inspection, it turned out there was a screw missing that attaches the top of the saddle to a plastic underbody. I don't know if it ever had the proper screws in it. I contacted Biktrix and told them it was a manufacturing defect. They said I would have had to reported it within 14 days. I spent $90 for a seat that only lasted 3 months. I don't know how I can trust Biktrix as a brand after this.