与测试模块合使用，提供便捷、安全的测量与校验操作。 插入测试盒时，联动测试盒内部接点先短接互感器侧CT二次电流回路，再隔离保护装置侧输入与相关出口/信号回路，实现先短接、后断开的时序逻辑。

主要特征：
测试把手型号统一，适用不同类型测试盒，无需区分使用。
测试把手设28个兼容4mm-DCC测试孔。
防误插设计，物理结构防止使用时把手插反，避免错接。
把手插入过程中，自动联动测试盒内部接点切换，无需额外操作。

Used with the test block for convenient and safe measurement and testing. During insertion, the plug first operates the internal mechanism to short-circuit the CT secondary, then isolates the relay-side inputs and associated trip/signaling circuits,providing a make-before-break sequence.

Key Features：
One universal test-plug type is suitable for all test-block variants.
Twenty-eight 4 mm DCC-compatible test sockets.
Keyed construction prevents reverse insertion and incorrect connection.
Insertion automatically operates the test-block contacts; no additional switching is required.