Long handle CobraHead
I would say that the CobraHead was the single most important tool in my gardening equipment, but I have three, the original, long handle and mini.
I had to replace the blade on the long handle. The blade fell out while I was ripping out a substantial patch of poison ivy by the roots. I'm on the edge of the woods, so it's endemic to the area. Birds like the berries.
The long handle enables you to tease out the roots of the vine often 6 to 10 feet long, without getting too close.
Unfortunately, the tapping screw loosened a bit and the blade fell out disappeared into the pile that had nurtured the poison ivy.