Review on SmartDoor by PetSafe - Dog and Cat Door Activated by Collar - Ideal for Small to Large Pets by Erin Dudley

UPDATED 11/29/2019 I thought the SmartKey came with a dead battery so I bought new batteries. However, the red light will flash to indicate a low battery. The old SmartKey works even though it is crumpled. After replacing the batteries, the old device will still work if the new one shows a too low battery level. This means that the new SmartKey itself is defective. and NO FREE REPLACEMENT. The shipping costs are roughly the same as the original key. The SmartKey is loose enough for any dog to chew through and in the 10 years that they have had this product they have never reformatted the SmartKey to sit flush with the collar. My workaround (pictured) for the dangling part was to get the buckled collar and slide it off the loose end. The problem is that I wanted a martingale collar that is usually made with clips instead of buckles (often incorrectly called buckles instead of clips). I have only found one satisfactory collar: https://www.amazon.com/gp/product/B07ZTT2N2Y/