The dual or attachable door draft stoppers go by different names - twin, double, under door draft stoppers, but they function all same. They are a single piece that slides under the door and "stops" both sides of the door.
Are they any good?
The short answer is no. That's why we don't make them.
Most dual/attachable door stoppers are made cheaply in China or Hong Kong and either don't stay on the door, or if they do, they don't seal properly.
We have been making draft stoppers for 16 years and we don't make two sided ones. We sell traditional one sided door draft stoppers. For a draft stopper to be attachable (or two sided), it needs to be very light. Ours are heavy so that they seal well. To be attachable (or two sided), a draft stopper also needs to be stiff, like a hard foam tube, ours are pliable so they seal well.
Problems with attached or dual draft stoppers include:
- Won’t stay on the door
- Won’t work with carpet or thresholds
- Scratches wood floors
- Because they are stiff and light, they don’t seal the draft
- Not attractive
If you have a door that isn’t suitable for a traditional draft stopper, please consider purchasing a door sweep available at any hardware or home improvement store (or online). It attaches to the door and doesn’t create the problems mentioned above. While it doesn’t provide the draft stopping power of a traditional draft stopper, it works as well as attachable or dual draft stoppers as far as reducing the draft.