Avoid Duplicate value .

Question

This is my code get subcatgeory Name in list  it's working fie.But i have face a problem showing duplicate value in list

For e.g. Subcategory name Drills -Drills show 5 time . I want to show only once . 

@{ int counter = 0;

foreach (var item in @Model)

{

if (counter == 0)

{

<li role="presentation" class="fs-12"><a href="#" aria-controls="blocking" class="active show" role="tab" data-toggle="tab"> @item.SubCategory </a></li>

}

else

{

<li role="presentation" class="fs-12"><a href="#" aria-controls="blocking" class="show" role="tab" data-toggle="tab"> @item.SubCategory </a></li>

}

counter = counter + 1;

}

}