How to set up slacklines without trees

Opis:
We did a job with Andy Lewis and this is how we set up temporary slacklines without trees. The bolts we used can be bought at https://amzn.to/2VpKaTJ and the chains I used were the cheap 400lb rated ones from my local hardware store. A great starter slackline if you like rachets is https://amzn.to/381F1nz or if you want to have 1' buy this one https://amzn.to/2vb682h