Case for use with portable radio station Baofeng DM-1801. Installing 3500 ma / h batteries in the case will increase the battery life of the radio by almost 60 percent! On the body there is a marking of the polarity of the installation of the elements, but if you suddenly install them "upside down", the glow of the red LED will signal you about a violation. Never install a case with a glowing red LED on the radio station, it can lead to its failure! The case has no protection against overdischarge of lithium cells. The battery discharge is monitored by the electronics of the radio station itself. Only unprotected lithium 18650 batteries can be used with the case. Since the case has a thicker shape compared to the original battery, the belt clip will not work correctly. For the clip to work correctly, you need to install it using the spacer supplied with the case. This requires 10 mm long m2.5 bolts. included in the package.