UPDATE: 2020-11-30 V1 OBSOLETE. Replaced by V2 after exteive testing. Detailed itructio provided. See listing: USB filtered antimicrobial mask exhaust. Work in progress prototype listing with more detail to follow. Still undergoing testing, use with caution. Designed specifically to help solve the problem of humidity build up and misting when using sealed clear masks. Basic itructio provided in pdf. Prototyped on the Eye Cu Smile V2 traparent mask kit using PVC plastic : Update 2020/11/08: Updated 30mm_fanCover to V1_1 Wider screw holes for easier fit. Removed exit bar for better airflow Minor ease of printing changes Update 2020/11/08: Research indicates that Lifeventure HydroFibre Quick Dry Towel with permanent Polygiene natural silver salt antimicrobial treatment is the best evaporative towel : Will update one testing complete. Now printing mini gyroid mesh at 75% on 0.6mm nozzle by lowering infill flow to 96% and speed to 10mm. Must make the PLActive gyroid mesh as fine as possible. Added reference material to bottom of listing. Features: Clamps to any flexible mask. Cut 25mm hole, practice on another material fit. 30mm WIINN USB LED fan. Plug into any USB battery pack, even smaller ones should last a day. Shown with blue led light fa as per itructio as a power indicator. Uses 4 ply evaporative sports towel as filter media, adjust ply count as necessary to seal for thickness of evaporative material used. Velocity stack to increase air velocity. Toroidal vane fan inlet silencer to help breakup fan resonant modes. Sealing edges to eure air tight seal to mask and filter media. Nitrile glove check valve to eure vapor moves 1 way out of mask. Copper3D PLActive Mesh to sterilize any large outgoing vapor droplets like a mesh vane demister. See listing for how to print. Alternative spacer provided for non antimicrobial materials to clamp filter media and retain check valve disk. Quick Tips: Standard black plastic fa can be used if don't need power indicator and don't want cyberpunk look. Thread is small and delicate due to part size, when tightening be careful not to go crazy and shear the thread, clamps and seals to PVC sheet without much force. For high exertion activities, eg factory floor, use 2. Disclaimer: I have no way of testing the viral load of any remaining vapour exhausted to air. Hence it should not be used where accredited PPE is already available in a professional setting eg healthcare. The design is unproven, therefore no guarantee can be provided as to its efficacy to filter viral particles. This is a prototype device intended to aid development of clear mask technology and should be viewed as such. References: On-Mask Chemical Modulation of Respiratory Droplets (Nov 2020) MESH & VANE MIST ELIMINATOR (2016) New material for the wire mesh demister (Jan 2013) Can Antiviral Fabrics Protect You From Getting COVID-19? (Sept 2020) Progress and Pepective of Antiviral Protective Material (June 2020) All Surfaces Are Not Equal in Contact Tramission of SA-CoV-2 (Nov 2020) Copper3D uses 3D printing to combat HIV tramission during breastfeeding (Feb 2020)