It looks like you're referring to a specific size of an air filter, likely a HEPA (High Efficiency Particulate Air) filter, given the dimensions you've provided: 490*287*300 mm.

To provide more context or assistance, could you please specify what you're looking for regarding this filter size? Are you seeking information on:

1、Compatibility: Is this filter compatible with a specific air purifier or HVAC system?
2、Specifications: Detailed specifications such as filtration efficiency, material, or frame type?
3、Replacement: Where to find a replacement or how to replace it?
4、Application: The typical applications or environments where such a filter is used (e.g., residential, commercial, cleanrooms, etc.)?

Providing more details will help in giving a more accurate and helpful response.