THESE MOUNTING PLATES ARE THREE-DIMENSIONALLY MANUFACTURED. They are non-oem plates. But they work perfectly. 

These are specifically designed for to fit the following Kidde models:

900-CUAR
KN-Cope-Ic
KN-COSM-IB
KN-COSM-IBA 
P4010ACSCO

And the following Firex models: 

FADC
ADC
AD
1275
1286
1285
PI2000
i4618





These WILL NOT fit the i2000 series devices. SMOKE DETECTOR IS SHOWN AS PHOTO DEMONSTRATION ONLY. KN-COSM-IBA DETECTOR IS NOT INCLUDED.

Includes one mount base, screws, and drywall anchors.

Being that they are printed, plates may show various imperfections, blemishes, extrusion lines, etc. 

Please see photos.