These simple Airlocks (Traps) are Handy for Fermenting buckets or bins as they have short stems which makes them suitable for the standard bin lid bungs with shallow apertures. Very effective and quieter than standard Bubbler Airlocks, these are definitely "Handy" and easy to use, simply half fill the chamber with cooled, boiled water and watch the fermentation through to completion without allowing bacterial contamination, fluff, flies, dandruff or anything else airborne to enter the brew by raising the fermenter lid! . . . . You know it makes sense!