Before you buy, please check your DVR's pin-out defined is same as this one.

Car Reverse Backup Rear View Camera 4-Pin Male Connector To RCA Wire Power Harness Adapter Wire Female CVBS SignalCharacteristic:This 4-pin male may be required if you have an automatic reverse camera with a 4-pin female connector.To CVBS RCA female connector signal power adapter harness.Specifications:Size: 34cm Camere signal input connector: 4-pin maleOutput signal connector: CVBS (RCA) femalePower supply (VCC): ~ DC + 12VInternal power supply (VDD): ~ DC + 3.3VThe package includes:1 x camera signal harness