A 400mm long (Approx.) piece of 6mm Diameter Bungee Cord with a Metal Aglet on one end and a Knot tied into the other end!
The Bungee simply slides through a hole designed directly into the Level Body, so no special
attachments are needed.
The Bungee Cord is available from any local hardware store, just without the Aglet, so you can
easily replace it yourself if needed. Without the Aglet the end is likely to fray, but you can limit this by holding the cut end over a flame to melt the loose cord threads.
Of course we are also happy to supply them to you as well! But, if you do get your own, you can
cut it to whatever length you need.