AliMed® InvisiCoat® Head Donut protects the head, neck, and ears, and offload pressure from occipital protrusion to protect the patient from pressure injuries and possible blindness. Also use to protect knees in prone. Recommended for use during supine, lithotomy, Fowler's, Trendelenburg, and Reverse Trendelenburg. Available in two sizes. Pack of 6.Small: 6"W x 1-1/2"H • Large: 9"W x 1-1/2"H • MR-safeCaution: Procedures at less than 60 kVp may produce slightly visible lines on edges of InvisiCoat Positioners. Always position the patient so the edge of the block will not be in the image field of concern. When tested at low attenuation of 80 kVp, results indicate an aluminum equivalency of 1%.InvisiCoat® Positioners, AliMed's award-winning innovation in patient positioning, features a rounded, seamless construction with unique curved edges specially designed to reduce artifacts and promote cleaner, clearer images. All positioners are coated with a durable, radiolucent finish that's impervious to fluids and embedded with antimicrobial silver for greater infection control. Recommended for use in the O.R., Imaging, MRI, and radiology.