The 1115 (THF-15) is the correct replacement for the following model:
The Lasko 1115 Humidifier Filter replacement is an equivalent version of the original Lasko 1115 Humidifier Filter. This humidifier wick filter replacement fits the Lasko Natural Cascade Humidifier Model 1115. The Lasko THF-15 humidifier filter has an antimicrobial agent that prevents hard water contaminants from growing in your humidifier.
Lasko 1128 Humidifier Filter TFH8 Replacement:
The Lasko THF-15 is a humidifier wick filter that helps your humidifier produce the cleanest, humidified air possible. The antimicrobial agent prevents things like mold and fungus from growing inside your humidifier, giving your Lasko humidifier the longest life possible.