Please note the App is only for Android system Product Name:HA11 24V Battery Equalizer Battery Voltage:2 x 12V Battery (Not included batteries) Function:For Balancing Battery Voltage Balance Current:0-5A HA11 24V Battery Equalizer HA11 battery equalizer is for balancing 2 x 12V battery bank. Compatible with lead acid battery, lifepo4 battery, NiMH Battery, etc. It start work when there is 20mv voltage difference between batteries. Model: HA11 Battery: 2 x 12V battery (Not included batteries) With Bluetooth Size: 70 x 70 x 27mm Weight: 0.25KG Please connect the battery equalizer to battery as follows: 1. Red cable: Battery B positive/+ pole 2. Black cable: Battery A negative/- pole 3. White cable: Battery B negative pole or Battery A positive pole. (The pole which connected Battery A and Battery B in series) Download the App:Please search "Blackbox battery equalizer" on for Google Play. Or scan the QR code in User manul to download the APP directly Monitoring Voltage by App: User can check battery voltage detailed curve by entering each Color: Black Material: Aluminum Alloy Package Contents: 1 * HA11 Battery Equalizer Balancer ( with cable )