The PREFER Trial has three main objectives. The primary objective of the trial is to show how much radiation attenuation is provided by XPF in absolute and relative terms. The secondary objective of the study is to measure and compare the amount of radiation that interventional radiologists are exposed to per case in an interventional suite setting using FDA approved XPF thyroid collars or standard 0.5 mm Pb equivalent thyroid collars. The third objective is to assess the operator comfort wearing the XPF protection devices. In order to achieve these objectives, measurements will be performed in 60 consecutive endovascular procedures requiring C-arm fluoroscopy performed at BCVI. Participants will be asked to wear an XPF cap (weighing approximately 100 grams) in every study procedure. Furthermore, a prospective randomization will be performed, assigning participants to wear their own standard 0.5 mm Pb equivalent thyroid collar or to wear the FDA approved XPF thyroid collar. Radiation exposure will be monitored with 4 radiation detectors (TLDs, 2 attached to the cap, 2 attached to the collar) which the participant is required to wear. After each procedure the participant will be asked to rate the comfort of wearing the devices on a scale from 1 to 100.