Root ISM DIV:

<div id="p7ISM_1" class="p7ISM ism-noscript ism-panels-5 ism-root-white ism-pad-30 ism-border ism-rounded ism-arrow-black" data-ism="1,600,1,1,0,8,0,0,1,0">

ism-panels-5 class sets number of panels to 5.

A media query resets the class so only 2 show at the 768px breakpoint:

@media only screen and (max-width: 768px) {
.ism-panels-5 .ism-panel {min-width: 50% !important;}
}