foreach ($maxServiceWeights as $code => $weight) {
    $shipAPI->setMaxServiceWeight($code, $weight);
}
//**********************************************************************
// Set Maximum Package Dimensions per service for package splits: OPTIONAL
// (Default is dervived maximum service volume as established by carrier)
// This setting will not exclude items which exceed values; it governs
// when to split to the next package
// (settings higher than service maximum are ignored)
// (typically fed in from your seller account configuration)
//**********************************************************************
// Length-Width-Height
$maxServiceDimensions = array('UPSGND' => "20-15-12", 'UPS3DS' => "20-15-12", 'UPS2DA' => "20-15-12", 'UPSNDS' => "20-15-12", 'UPSNDA' => "20-15-12", 'FDXGND' => "20-15-12", 'FDX2D' => "20-15-12", 'FDXES' => "20-15-12", 'FDXFO' => "20-15-12", 'USPPP' => "12-15-12", 'USPPM' => "12-15-12", 'USPMM' => "12-15-12", 'USPEXP' => "12-15-12");
foreach ($maxServiceDimensions as $code => $dims) {
    $dim = explode("-", $dims);
    $shipAPI->setMaxServiceLength($code, trim($dim[0]));
    $shipAPI->setMaxServiceWidth($code, trim($dim[1]));
    $shipAPI->setMaxServiceHeight($code, trim($dim[2]));
}
//************************************************************
// Flag Carrier for Flat Rate Box Qualification: OPTIONAL
// Item Dimensions are required
// AuctionInc will price service at the better of the
// flat (if item/s fit) or calcluated rate
// USPS (Priority Mail (boxes, envelopes), Express Mail (envelopes)
//    -- valid values: PKG / ENV / ALL
// FEDEX (International Priority (boxes)
//    -- valid values: PKG
// (typically fed in from your seller account configuration)
//************************************************************
$shipAPI->setFlatRatePackaging("USPS", 'PKG');