The Otterbox Alpha glass screen protector is compatible with Otterbox cases. If placed properly, the Otterbox case will not interfere with the screen protector. I placed a Zagg glass screen protector on my Note 9. However the space tolerance between the Zagg glass screen protector and the internal polycarbonate case is very small. Thus, if the Zagg screen protector is not absolutely centered on the screen, it can interfere with the internal polycarbonate case.