I bought a couple of these and some heavy duty keyed pad locks. I can tether the two cables together if I need it longer, but usually one does the trick. I secure my EU3000 in the back of the truck bed or to the frame of the TT or tree. It usually stays in the truck and I always cover it up when not in use. The EU3000 has a metal handle, but a determined thief is going to figure out a way. For me it's more of a deterrent and makes it not an easy target.
https://www.lowes.com/pd/Master-Lock-180-in-Gray-Steel-Keyed-Cable-Lock/1000004536