QMARK 10 Pack Electric Fence Wood Post Anchors, Wood Post Screw-in Insulators, Screw-in Gate Handle Anchor, 2-Ring Black Handle Anchors

Great heavy duty quality, surprisingly impressed. Only drawback is the length of the screw gives it a weakness. I would have preferred for it to be longer or to be through bolt to provide better leverage and support.

These are decent enough insulators, comparable to others I have used extensively. As with all of these types of insulators, drill a pilot hole in hardwood and don't overtighten or you'll break the plastic. Especially if you're using a drill chuck. I don't know what 'engineering plastic' is, we'll see if it holds up over time.