J-clip remover pliers are essential for removing j-clips, should you need to do any cage repairs or modifications, or remove a j-clip that got tightened around only one wire accidentally. Each "jaw" has a triangular "tooth." Grip the j-clip with one tooth in each side and squeeze. The pressure forces the j-clip to open, and you can then pull it off the wire.
If you intend to build more than a few of your own cages, you'll find these j-clip remover pliers to be indispensable. You can try to pull and prod the j-clips off with assortments of pliers, screw drivers, needlenose pliers, etc. I tried that myself, back in the day. It was utter frustration and a huge waste of time. I broke down and bought these remover pliers, and never looked back.
This j-clip remover is high quality, and heavy-duty. With periodic maintenance,
such as oiling of the joint and exposed metal (especially in humid climates
like the Pacific northwest), this removal tool will keep on delivering for many
years. I've been using my j-clip removers for years. They show some
discoloration of the metal, yet with periodic oiling, continue to work perfectly. Can't ask for much more!