All devices which do not have a galvanically insulated internal power supply - mainly these are RS and MS - have a built-in impedance to discharge capacities.
E. g.:
RS2-TX, MS20/30, MS4128: 3 MOhm
RS20/30: 5.3 MOhm
SPIDER II: 10 MOhm
RSP: OpenBAT: 20 MOhm
MSP: 40 MOhm
Note: the displayed values might vary slightly due to tolerances of the resistors.