At a friend's yesterday, need to use their extension reel, at first it worked ok, then later it did not, plugged my socket tester into it and sometimes it showed good wiring, other times poor earth loop value.
took the plug-end apart and found the earth pin had no screw in it (or rather it was rattling about inside the plug, also the neutral pin had no screw in it, from the ferrule not being crushed it looks like the neutral pin never had a screw in it, the neutral pin was blackened and the ferrule itself was partly melted.
beware
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Doesn't look like it's a current model, and obviously JCB has just rented out its name for branding.