You can spam these all over the borders of your base for protection since they act as a 2x3 metal structure, after you place all of the gates you can then enter your base from any side even on mounts since every "wall" protecting your base is a gate. It is slightly more expensive than using 6 metal walls and 2 metal fence foundations though as you need 205 metal and 60 cementing paste versus 170 metal and 46 cementing paste.

Use these to trap carcha they can't break them