_product.html.erb

<%= content_tag :li, class: product.primary_collection.to_param do %>
  <%= link_to collection_product_path(product.primary_collection, product) do %>
    <div class="thumbnail">
      <%= product_thumbnail(product) %>
    </div>

    <div class="summary">
      <h3><%= product.name %></h3>
      <p class="type"><%= product.type_name %></p>
      <% if product.manufacturer_name.present? %>
        <p class="brand">By <%= product.manufacturer_name %></p>
      <% end %>
    </div>
  <% end %>
<% end %>