The wire legs are formed in such a way, so that they spread outwards when the small spring is moved towards the center.
The spring can be slid forward, to hold the ends closer together.
As I closely examined the construction, I realized Chris came up with an ingenious way of building the tool. He had inserted a piece of plastic tubing inside the copper tubing.
When the threaded eye is twisted into the end of the handle, the screw will force the plastic outwards forming a secure joint at the end.
Brilliant idea Chris. I look forward to using this tool in the future. It has also gotten me thinking about making other tying tools.