Cannot get value of selected radio button in side variable in vue.js

I'm generating Radio button dynamically :

<span  v-for="val in product.value" :key="val.id">
<input v-model="product.user_value" :id="val.id" :name="product.name" :v-bind:value="{id: val.id, name: product.name}" :type="radio"/> </span>

It is generating radio button groups as :

Product 1   Product 2

So if i select anyone of them Like i select Product 2, then i cannot get new selected value in the product.user_value.

via Chebli Mohamed