This plastic Airlock from Hambleton Bard has a very large water chamber making it ideal for long-term fermentation without risk of it drying out.
Will fit a fermentation bucket or fermenter drilled to accept a Better Brew orange/brown grommet. Alternatively, attach to a length of 10mm syphon tube and a water-filled jar to create a “blow off” airlock.
With cap in place, screw lock firmly into bung.
Fit bung tightly into fermentation vessel.
Remove cap and fill lock with approximately 12mm of water.