The BlackVue DR900X / DR750X Series Rear Camera Mount Bracket RM-75 will compatible with following BlackVue dashcam Models
DR900X-2CH Plus rear camera
DR750X-2CH Plus rear camera

Also compatible with following models
DR900X-2CH rear camera
DR750X-2CH rear camera
DR900S-2CH rear camera
DR750S-2CH rear camera
DR650S-2CH rear camera