I cut open all my used filters to check out the construction and recycle the steel parts. For the 5 years I have been using these filters they have always looked great. Silicone valve, metal end caps and nice even filter pleats. All except for the last one. It was MISSING an end cap! It didn't fall off or come unglued it just never made it into the filter. This left the end of the pleats totally open rendering the filter mostly useless.