The JA-81M is designed to detect the opening of doors, windows etc. It can also be extended by a normally closed / normally open sensor connected to its wired input. It is also designed to detect the mishandling of roller blinds. This is achieved by being wired to a device detecting ratchet-wheel movements. Small movements are filtered out so that random wind blasts do not cause false alarms. The battery-powered detector communicates via OASIS radio protocol.

Specifications
- Voltage: Lithium battery LS(T)14500 (3.6V AA)
- Typical battery lifetime: approx. 3 years for 20 daily activations maximum
- Communication band: 868 MHz, Oasis protocol
- Communication range: approx. 300m -( open area)
- Typical sensitivity range of the built-in magnetic sensor: 45 / 25mm
- Inputs for external sensors: IN2 and TMP = normally closed loops / IN1 normally closed or balanced loop (1k resistor)
- The maximum length of the cable for external detectors: 3 meters
- Dimensions: 110 x 31 x 26 mm, magnet: 56 x 16 x 15 mm
- Operational environment: II. Indoor general, according to EN 50131-1
- Operational temperature range: -10 to +40 °C
- Classification: Grade 2, EN 50131-1,CLC/TS 50131-2-6, EN 50131-5-3
- Complies with: ETSI EN 300220, EN50130-4, EN55022, and EN 60950-1
- Can be operated according to: ERC REC 70-03