This extension works with TWO different gate models, the SS-30 and the MG-15
SS-30 gate is expandable width from 27” to 42.5”. Add the 10.5” extension to that gate and the maximum width is 53 inches.
MG-15 gate is expandable width from 26.5” to 40.5”. Add the 10.5” extension to that gate and the max width is 51” inches.
Both gates ( SS-30 and the MG-15) are adjustable width. The extension is fixed width
Refer Instruction Manual under Technical Specification