private/dev/Get-MyDeviceProduct.ps1

function Get-MyDeviceProduct {
    [CmdletBinding()]
    param ()
    $deviceManufacturer = Get-MyDeviceManufacturer

    if ($deviceManufacturer -eq 'Dell') {
        $deviceProduct = ((Get-CimInstance -ClassName CIM_ComputerSystem).SystemSKUNumber).Trim()
    }
    elseif ($deviceManufacturer -eq 'HP')  {
        $deviceProduct = ((Get-CimInstance -ClassName Win32_BaseBoard).Product).Trim()
    }
    elseif ($deviceManufacturer -eq 'Lenovo')  {
        #Thanks Maurice
        $deviceProduct = (Get-CimInstance -ClassName Win32_ComputerSystem | Select-Object -ExpandProperty Model).SubString(0, 4)
    }
    elseif ($deviceManufacturer -eq 'Microsoft')  {
        # Surface_Book or Surface_Pro_3
        $deviceProduct = ((Get-CimInstance -ClassName CIM_ComputerSystem).SystemSKUNumber).Trim()
        # Surface Book or Surface Pro 3
        # $deviceProduct = ((Get-WmiObject -Class Win32_BaseBoard).Product).Trim()
    }
    else {
        $deviceProduct = (Get-MyDeviceModel).Trim()
    }
    return $deviceProduct
}