Motorola makes the most widely used one, and you can see that they're used by Secret Service, they're used in combat, it's a very, very common standard in the U.S. and elsewhere.
摩托罗拉是这电话的最大生产商，你也会看到 它们是被秘密机构以及战场上所使用， 它在美国和其他地方都非常~非常的常见的标准。