Optimal Size for Versatility and Convenience: our pre-filter has a size of 36.5 x 17.5 cm/14.4 x 6.9 inches, and features a thickness of 8 MM; It's nicely compatible with most soldering fume extractors on the market today; These dimensions provide ample space to collect heavy smoke and dust, maximizing its efficiency and ensuring a safer, cleaner work environment Effortless Installation for Optimal Functionality: the installation process is as simplified as possible thanks to our specially designed pre-filter system; All you need to do is to install the cotton pre-filter onto the fume extractor's HEPA and activated carbon filters, then secure the device back to its original place; There's no need for measurements or cuts, allowing quick and easy setup and operation Designed to Extend Filter Lifespan and Efficiency: our pre filters cotton are the first line of defense in your fume extraction system; Capable of filtering PM50 smoke and larger airborne particles such as sawdust, hair, iron fillings, paper, they effectively extend the primary filter's lifespan by capturing these particles before they reach the main filter; Wide Application Scope: our pre-filter cotton replacements are not limited to soldering smoke removal; It's also effective in dust removal, laser smoke purification, DTF harmful gas removal, beauty salons, printing, and welding; It's designed to keep your workspace clean and safe and improve the air quality of your workplace Ample Supply for Continual Use: with each purchase, you will receive 10 pre-filter replacement pieces; This generous quantity ensures optimal filter performance and provides a sufficient supply for prolonged use Color: White Material: Polyester fiber Package Contents: 20 Pcs x Pre Filter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.