Which is Odoo website user group? - odoo

Question

I'm new in odoo so sorry if this is a noob question.
How can I assing unlogged website user read permission to the model?
which is the website user group?
And why odoo 8.0 documentation so poor?
I've made a module website_downloads:
models:
class Files(models.Model):
_name = 'website_downloads.files'
name = fields.Char()
file = fields.Binary('File')
filename = fields.Char()
controler:
class website_downloads(http.Controller):
#http.route('/downloads/', auth='public', website=True)
def index(self, **kw):
files = http.request.env['website_downloads.files']
return http.request.render('website_downloads.index', {
'files': files.search([]),
})
website template:
<template id="index" name="Website Downloads Index">
<t t-call="website.layout">
<div id="wrap" style="margin-top:50px;margin-bottom:50px">
<div class="container text-center">
<table class="table table-striped">
<t t-foreach="files" t-as="f">
<tr>
<td align="left"><t t-esc="f.name"/></td>
<td><t t-esc="f.filename"/></td>
<td><a t-attf-href="/web/binary/saveas?model=website_downloads.files&field=file&filename_field=filename&id={{ f.id }}"> <i class="fa fa-download"></i> Download</a></td>
</tr>
</t>
</table>
</div>
</div>
</t>
</template>
security
id,name,model_id:id,group_id:id,perm_read,perm_write,perm_create,perm_unlink
access_website_downloads_user,website_downloads.files,model_website_downloads_files,base.group_user,1,0,0,0
access_website_downloads_manager,website_downloads.files,model_website_downloads_files,base.group_sale_manager,1,1,1,1

Answer 1

"base.group_public"
I solved adding this to the security file
access_website_downloads_public,website_downloads.files,model_website_downloads_files,base.group_public,1,0,0,0