Battery operated - 9v. Low battery and fault warnings. Audible and visual alarms. Test/reset button. Wall-mounted and freestanding. Size: H9 x W11.5 x W3cm
CommentsGood points: Alarm triggered within three minutes and noise level was over 85db during testing. Small, discreet and easily portable. Thorough instructions.Drawbacks: No display. No peak level indicator.