SimpleForm (and Ransack) with Bootstrap 3, needing "checkbox-inline" style without the extra "label" field that simple-form seems to like to generate. Manually adding the collection wrapper div.

collection_check_boxes.html.haml

= search_form_for @q, url: my_path, html: {method: :get} do |f|
  .row
    .col-md-4
      .form-group
        %label.string.required.control-label= "Years Teaching"
        .row-link
          = f.collection_check_boxes :contact_info_profile_teaching_history_subject_taughts_years_teaching_in, TeachYears.all, :id, :name, {item_label_class: "checkbox-inline", item_wrapper_tag: false, boolean_style: :inline } do |b|
            - b.label(class: "checkbox-inline") { b.check_box + b.text}

fragment.html

<div class="col-md-4 ">
  <div class="form-group">
    <label class="string required control-label">Years Teaching</label>
    <div class="row-link">
      <label class="checkbox-inline" for="q_contact_info_profile_teaching_history_subject_taughts_years_teaching_in_1-5_years">
        <input type="checkbox" value="1-5 years" name="q[contact_info_profile_teaching_history_subject_taughts_years_teaching_in][]" id="q_contact_info_profile_teaching_history_subject_taughts_years_teaching_in_1-5_years">1-5 years
      </label>
      <label class="checkbox-inline" for="q_contact_info_profile_teaching_history_subject_taughts_years_teaching_in_6-10_years">
        <input type="checkbox" value="6-10 years" name="q[contact_info_profile_teaching_history_subject_taughts_years_teaching_in][]" id="q_contact_info_profile_teaching_history_subject_taughts_years_teaching_in_6-10_years">6-10 years
      </label>
      <label class="checkbox-inline" for="q_contact_info_profile_teaching_history_subject_taughts_years_teaching_in_over_10_years">
        <input type="checkbox" value="over 10 years" name="q[contact_info_profile_teaching_history_subject_taughts_years_teaching_in][]" id="q_contact_info_profile_teaching_history_subject_taughts_years_teaching_in_over_10_years">over 10 years
      </label>
      <input type="hidden" name="q[contact_info_profile_teaching_history_subject_taughts_years_teaching_in][]" value="">
    </div>
  </div>
</div>