qx modular crane packages are pre-engineered, complete crane component packages utilizing cutting edge technology including the innovative spacemaster sx wire rope hoist. variable frequency drives are standard on trolley ......qx modular crane packages are pre-engineered, complete crane component packages utilizing cutting edge technology including the innovative spacemaster sx wire rope hoist. variable frequency drives are standard on trolley and bridge motions for smooth starts and stops. plug-in electrical cabling and bolted structural connections simplify assembly.