To use this Barco projector lens, first make sure it's properly attached to your Barco RLM - W6 or RLM - W8 projector. When installing, handle it gently to avoid any further damage. During use, keep the lens clean. You can use a soft, dry cloth to wipe it if it gets dirty. Don't use harsh chemicals as they might damage the lens. Since there's a small scratch on the rear glass, it might not affect normal use too much, but just be aware of it. When storing the lens, put it in a dry and dust - free place. And always be careful when moving it around to prevent any new scratches or other damage.