These would have to be the most versatile relay cards on the market.
Each relay can be operated by TTL levels, NPN and PNP open collector or 0 to 12VDC.
Each relay has two inputs, marked LO and HI.
As the names suggest a low on the LO input will operate the relay.
Similarly a high on the HI input will also operate the relay.

Specifications:
Operating Voltage 12VDC
Input low voltage (LO) 0 - 0.8V
Input high voltage (HI) 2.4 - 12V

We have operated these relays from an old style TTL 7404 Hex Inverter which have less drive capacity than the newer HC and HCT types.
The inverter could operate the relay with both a low and a high output signal.
But what is more important was that the High voltage dropped from 4V to 3.5V showing the output still had capacity to drive other TTL devices

Each single pole changeover relay contacts SPDT will switch 10A/24VDC , 10A/110VAC, 5A/240VAC.
Coil Resistance for the relays is 400ohm(12V)
Current consumption for 2 relay card (12V)
All relays off 4mA
One relay on 37mA
Two relays on 70mA
A LED shows the state of each relay .
The Relay Cards are available in 12VDC or 24VDC
Four 3.5mm holes in each corner allow easy mounting on a panel

Dimensions of card 2 relay card - 42(L) x 71(W) x 20(H)mm

DIN RAIL MOUNT for RLC122 DIN122

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