Abstract: Depth detector assemblies for material handling attachments are disclosed. In some embodiments, the depth detector assemblies may include at least one ultrasonic sensor removably attached to the material handling attachment. The depth detector assemblies may additionally include a controller removably attached to the material handling attachment and capable of receiving signals from the at least one ultrasonic sensor. The depth detector assemblies may further include a light display capable of being selectively illuminated by the controller to indicate depth of a load relative to the material handling attachment based on the received signals from the at least one ultrasonic sensor.