I'm looking for a dust extractor to fit my table saw. I'm considering the RSDE1. As a fair bit of fine dust is produced, will this extractor it filter down to 5 micron or better? Would I be better off buying one of the bigger models with twin filters now assuming my requirements will increase in the future? 

The RSDE1 has a capacity of 45 litres which will be fine for light to medium use of fine dust producing machines such as table saws and bandsaws etc. If you use or plan to use the extractor for machines such as a planer thicknesser which produces large volumes of chips then a larger extractor such as DX4000 or DX5000 will provide extra power and increased collection capacity. The filtration of the RSDE1, DX4000 and DX5000 is 0.5 micron filtration as standard and our extractors have been tested and certified by a 3rd party test house to verify filtration.