So I bought one of those BS-400 u-locks for my bike. But being in a rush to use it, I accidentally discarded the small plastic screws that are supposed to attach the holding bracket to the bicycle frame. These are special plastic screws that are impossible to find in regular hardware stores. The solution was to contact Trelock staff in Germany, who mailed me back two plastic screws, no charge at all. Happy customer, returning customer. I will always prefer Trelock to anything else. Thank you Trelock !!!