template select image size

Hi,

my template has: <img src="<perch:shop id="image" type="text" />" class="img-responsive" alt=""/>

but want to select the smaller image which is 375px high:

<perch:shop id="image" type="image" label="Main image" order="6" height="1200" bucket="shop" /> <perch:shop id="image" type="image" order="6" height="800" bucket="shop" /> <perch:shop id="image" type="image" order="6" height="375" bucket="shop" /> <perch:shop id="image" type="image" width="80" height="80" density="1.6" crop="true" bucket="shop"/>

what to I need to add to <img src="<perch:shop id="image" type="text" />" class="img-responsive" alt=""/> to select image of height 375px

thanks in advance

tony