derrick head cargo block 吊杆头起货滑车 ; 吊杆头起重滑车 ; 上吊货滑车

derrick head block 吊杆头滑车

derrick head span block 吊杆头跨绳滑车

derrick head purchase block 上吊货滑车

derrick head fitting 吊杆端配件

derrick head shipment block 吊杆头起货滑车

derrick k head cargo block 吊杆头起货滑车