According to Huawei's official product specifications, Huawei 50W wireless car charger is designed to support 50W wireless fast charge, and 40W wireless fast charge is another power standard. Although both are wireless charging, the power is different, so Huawei's 50W wireless car charger may not be compatible with 40W wireless charging devices. It is recommended that you carefully review the product specifications and compatibility instructions before purchasing to ensure the compatibility and best charging effect of the charging device.