woocommerce choose an option button not responsive

The woocommerce choose an option button is not fitting within the screen on iphone, the rest of woocommerce is.
My theme Tyros is responsive.
I have spent ages looking for an answer and no-one else seems to have this problem. Also my related products at the bottom are non responsive so I have removed them for the time being.
I have <meta name=”viewport” content=”width=device-width, initial-scale=1″
in the head.
Any clues?

Thanks in advance