Mercury - Case-dmt meter - 91-854014T. The Mercury Case-dmt meter - 91-854014T is a precision-engineered protective case designed to securely house and safeguard your Digital Multimeter (DMT) tool. Whether you're servicing electrical systems dockside or storing tools onboard, this rugged case helps ensure your diagnostic equipment stays protected from impact, moisture, and corrosion.. Key Features. Custom Fit for Mercury DMT Tools - Designed specifically for the Mercury digital multimeter. Hard-