Ultrasound B-mode Box Labeling

I have a batch of ultrasound still frames on an internal labeling server and I need every image annotated with a single bounding box that covers the full grayscale B-mode panel—nothing more, nothing less... (Budget: $10 - $30 USD, Jobs: Computer Vision, Data Annotation, Data Labeling, Data Management, Deep Learning, Image Analysis, Image Processing, JSON)