<?php

$var = 'size=s3435/user=Synergy';
$temp = explode('/', $var);
//Fetch size
$pos = strpos($temp[0], '=');
echo substr($temp[0], $pos+1);

//Fetch user
$pos = strpos($temp[1], '=');
echo substr($temp[1], 0, $pos);
echo substr($temp[1], $pos+1);
?>