Question about Silhouette PixScan cutting underlay

PixScan 8.5x11.5 in (21.6x29.2cm): Yes.
On the manufacturer's page Silhouette says: for Cameo 4, also compatible with Cameo 1,2,3.
When I measure it, it is 32.5cm wide, the black frame has a width of 29.8cm).