"This item used to be threaded internally and therefore screwed onto the top of the 5/8" expandable earth rod (87633), providing a secure fit with good contact area. Brilliant!
The latest delivery was unthreaded and can't easily be passed over the threads at the top of the rod. Even if you manage to force it on, it's then only clamping onto the tips of the thread. Far less secure and very poor contact. If you fit it further down the rod, it leaves a big chunk of rod sticking up that prevents the assembly fitting under a standard MK earthing-point box. Hopeless!
"This clamp is too big for the 5/8 rod. It will clamp onto the rolled threads but not the main shaft of the rod. This doesn't make for a particularly reliable connection and given that you sometimes end up cutting the rod to length is not right good."