Lightweight, durable, and will not rust. Indeed, this design creates maximum airflow for maximum pack. Fits all Exmark walkbehinds and Exmark Vantage stand-on. Recently installed mulch kits on my primary equipment and will be using my commercial 21 to bag when needed. Used gently only one season. Purchased in 2013 for $400.00; will sale for $250.00. I am located in the Northern Virginia area.