Review on Efficient Drain Spud #4223 by Aprilaire: Superior Quality for Optimal Performance by Christine Gauthier

A worthy alternative to the more expensive Honeywell Whole House humidifier drain. There are 2 small pointed tabs on the side that hold it in place. But the distance between the tongue and the top shelf protrusion is only a little short, less than 1/4 mm. Use a simple file to peel off the thin paper discs until they twist and snap into place. If you don't block it, the funnel will pop out a little when you reconnect the drain to it. Otherwise, the funnel fits perfectly into the hole. You don't have to file it, but I like it when it's a little more secure than the weight of the filter holding it in place.