Model "product.product" have a field "product_tmpl_id" which is "Many_to_one" to model "product.template".

Now, I have a record of "product.template". As well known, that there aren't any field which is "One_to_Many" to "product.product". So what is the simplest way to get recordset of "product.product" from this single "product.template" record?

Please give me some advises. Thanks