

MR30-BU-NR4
| product description | Relay base unit module |
| Terminal type | Push In terminal |
| voltage | 24 V DC |
| Reverse polarity protection | support |

MR30-BU-NS
| product description | Standard base unit module |
| Hardware Expansion | Conductive potential unit (DC24V) |
| voltage | 24 V DC |
| Reverse polarity protection | support |

MR30-BU-P
| product description | Power Base Unit Module |
| Hardware Expansion | Construct a new potential group (DC24V) |
| voltage | 24 V DC |
| Reverse polarity protection | support |