FixtureDisplays X-ray Protective, Radiation Safety Leaded Cap for X-Ray MRI CT Radiation Protection 15455 The X-Ray, MRI and CT Radiation Protective, Radiation Safety Cap offers great protection for head for X-Ray, MRI and CT Radiation radiation. Adjustable Hook and Loop tab allows for custom fit. Navy nylon cover. Hat opens on the back with hoop and loop fastening strips. Top of hat has circumference of 24". Bottom of hat at full extension has circumference of 26". Smallest you can adjust to is 21" circumference. 0.50mm Pb. Shipping to Canada and Mexico: import duty and fees apply.