1, If you are looking for a latching relay with power-off memory, then this module will be very suitable for you. Even if the power supply is turned off, the status of the output switch will not be affected in any way, it will remain in the state before the power was turned off. 
2, This is a simple and practical latching relay module, which is very convenient to use. It can support both Normally Open and Normally Close. Two screw mounting holes are convenient for you to fix it on the wall or wooden board. Of course, you can also choose not to lock the screw. Compact plastic case and wires connects for easy mount.
3, Support three input control modes: 1, Use Set and Reset buttons on the module(No external control switch or signal is required). 2, External Set and Reset button(Support Momentary-action switch, but can't support Self-holding switch). 3, for Sink/NPN output controller.
4, Operating voltage version: DC 5V, 12V and 24V three versions selectable. Output switch DPST 1NO 1NC(Double Pole Single Throw, 1x Normally Open and 1x Normally Close ), rated current 8A/250VAC or 8A/30VDC (for one switch).

Datasheet: https://www.czh-labs.com/tmp/madeimg/datasheet/f-1030.pdf