Originally I purchased the 20-29gal conversion kit but I made the hasty decision to upgrade my tank to a 40gal, so I had to return the 20-29gal door and purchase a new 40gal door.
They sent me a shipping label and I was able to send back the original door and had the new door at my doorstep in less than a week with custom instructions. Super pleased and they provided excellent service throughout the ordeal even though I made an error on my behalf they had quick communication and helped me figure it out.