Check out example codes for "Radium requires each element with interactive styles to have a unique key, set using either the ref or key prop". It will help you in understanding the concepts better.

Code Example 1

<ul className='list-unstyled last__category'>
 <li>
 	<h5 style={style.listCategoryTitle} key={Math.random()}>
 	Tablet
 	</h5>
 </li>
 <li>
 	<a href='#/' style={style.listCategorySubtitle} key={Math.random()}>
 		Android
 	</a>
 </li>
 <li>
 	<a href='#/' style={style.listCategorySubtitle} key={Math.random()}>
 		IPad
 	</a>
 </li>
 <li>
 	<a href='#/' style={style.listCategorySubtitle} key={Math.random()}>
 		Windows Phone
 	</a>
 </li>
 </ul>

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