I would say the wire saw advertised looks very poor. I used one ages ago of similar design and it tried to friction burn its way through the limb - with nothing to hand I blew the limb off with 2 3" magnum loads. I have since used the saw on my leatherman to takes limbs off up to 4" in 'emergencies'. The leatherman is an exceptional piece of kit. I have seen saws that look like a chainsaw chain that look quite effiecient?