Transparent HDPE panels let a puppy watch the room instead of staring at a solid wall, and they let anyone check on play without leaning over the rail. Six panels assemble by hand into a 35-in square, a 69-in rectangle or a 67-in hexagon at a steady 22.5-in height. Dual safety locks on the 17.5-in by 21-in door cut the chance of an accidental opening. Suction cups grip smooth indoor floors and 6 ground stakes hold the pen on grass outside. Rounded corners and firm panel connections keep the 19.5-lb enclosure safe to lean against.