The Phelps Diaphragm Hat Clip lets you quickly access your Phelps Diaphragm while protecting your call by easily attaching to your hat, backpack, binocular straps, or anywhere you prefer. The Phelps Hat Clip uses a strong metal clip for tension. Install the Diaphragm in any direction. Features2 PKClips directly onto the bill of a capSecurely holds the diaphragm in place