Just got the aviator harness. How can i make it longer?

[Nir]

I just got the harness and i will start training mango with it tomorrow. however i noticed that the line is very small. just enough so i can walk around with him but not long enough to let him fly. Anyway i can make it longer? and the flight line from their site wont work since i live in nyc so there is no ground to stick that thing in. so i just need a way of extending the harness in a safe way while still holding the other end on my wrist. i was thinking about just tying a longer string to the end of the harness string but not sure if that would be safe.

so any ideas?

[Eric&Rebecca]

You can buy the extension 'lead' or flying line for it from the same company.