Earth stakes, connectors, gate handles, warning signage, and the rest of the hardware a complete electric fence system needs beyond wire, posts, and the energizer itself.
A working electric fence is a complete circuit, and the accessories in this category are what make the rest of the system actually function together — most importantly, the earthing kit.
The earth system — usually one or more galvanised earth stakes driven into moist soil — completes the circuit: when an animal touches the live wire, the pulse travels through the animal, into the ground, and back to the energizer through the earth stakes. A poor or undersized earth system is the single biggest reason an otherwise correctly installed fence feels weak, so it's worth sizing earth stakes to the energizer's output rather than treating earthing as an afterthought.
For a new installation, it's usually more efficient to work from a full parts list than to buy accessories one at a time — Quick Order generates a matched bill of materials (wire, posts, insulators, earthing, and accessories) from your fence length and application, which you can adjust before adding to cart or requesting a quote.