Interlocking

While wielding a shield with this property within 5 feet of a friendly creature who is also wielding a shield with this property, you can both use your reactions on either of your turns to interlock the shields. While interlocked, both creatures gain a bonus to AC equal to the interlocking number. If at any point the creatures are more than 5 feet from each other, the shields immediately de-interlock, and this effect ends.