Step 9: Electric Fence Insulator
Using one half cut a Z groove on the open end. Directly opposite of the bottle, but still on the open end, cut another Z groove, and make sure to make it a mirror image of the first.
Now, on the closed in, make a slit or large hole for your post to run through both sides of the bottle. Near the slit, make two small holes, either side of the post slit. Use this end to wire to the post, and run the electric fence through the Z groove.