3 rása sendir fyrir SECOLink kerfi. Gerir kleift að tengja 3 skynjara við kerfi t.d. vatnsnema eða önnur búnað með snertum.
| Features | BK1 | BK3 | BK4 |
| Description | Magnetic door contact | Transmitter with 3 inputs | Transmitter with 3 inputs and magnetic door contact |
| Compatible receivers | P series panels, EXT116s | P series panels, EXT116s | P series panels, EXT116s |
| Operating frequency | 868 MHz | 868 MHz | 868 MHz |
| Communication range in building | Up to 100m | Up to 100m | Up to 100m |
| Communication with hopping code | Selectable | Selectable | Selectable |
| 2-way technology | Yes | Yes | Yes |
| Contact Open transmission | Yes | Yes | Yes |
| Contact Close transmission | Yes | Yes | Yes |
| Tamper Changed transmission | Yes | Yes | Yes |
| Battery low status transmission | Yes | Yes | Yes |
| Supervision transmission | Every 1 hour | Every 1 hour | Every 1 hour |
| In-built magnetic contact | Yes | - | Yes |
| In-built inputs for external detectors | - | 3 | 3 |
| External detector = magnetic contact | - | OK | OK |
| External detector = roller type detector | - | OK | OK |
| External detector = vibration detector | - | OK | OK |
| Unique ID number for magnetic contact | Yes | - | Yes |
| Unique ID number for every in-built input | - | Yes | Yes |
| Power supply | Lithium battery, ½ AA, 3.6V | Lithium battery, ½ AA, 3.6V | Lithium battery, ½ AA, 3.6V |
| Battery life | >3 years | >2 years | >2 years |
| White color model | BK1 | BK3 | BK4 |
| Brown color model | BK1_br | BK3_br | BK4_br |
| Overall dimensions W x H x L in mm | 27 x 23.6 x 75 | 27 x 23.6 x 75 | 27 x 23.6 x 75 |
| Operating humidity | 0% - 70% | 0% - 70% | 0% - 70% |
| Operating temperature | -5oC up to +50oC | -5oC up to +50oC | -5oC up to +50oC |
