<p>Narrow Siqveland Matrix Retainers have a stainless matrix clamp system. These dental retainers have the following features:<br />
&bull;&nbsp;&nbsp; &nbsp;Narrow Pattern<br />
&bull;&nbsp;&nbsp; &nbsp;Adjustable<br />
&bull;&nbsp;&nbsp; &nbsp;Small knob<br />
&bull;&nbsp;&nbsp; &nbsp;Premium Grade</p>