Specifically, The Walkman Blog has spotted YY1304B and YY1305B, as well as the YY1303B that is rumoured to be the Walkman NW-ZX900. At this stage, no device photos or technical details about these unreleased Walkmans have emerged. Nonetheless, the website has still inferred some details based on past generations.
For instance, while retail names for YY1304B and YY1305B remain unclear, the same website suggests that these could be the NW-WM1AM3 and NW-WM1ZM3 based on past models. Likewise, Sony released the NW-A306 and NW-ZX707 around 3-4 months after they were certified by the IECEE. Hence, The Walkman Blog speculates that Sony is targeting January or February 2027 announcements, with these certifications having been issued on September 4, 2026.