| SPECIAL VERSION |
| Code | Description |
| RTL 510/AG | Local unit with relay output, wall mounting ; enclosure silver finish |
| RTL 510/AL | Local unit with relay output, wall mounting ; enclosure aluminium finish |
| RTL 510/B | Local unit with relay output, wall mounting ; enclosure black finish |
| RTL 510/GY | Local unit with relay output, wall mounting ; enclosure grey finish |
| ACCESSORIES |
| Code | Description |
| ASA 2418 | Cable for powering RTL 1.. and RTL 5.. directly with 24 V AC |