Our extra impression putty is provided just in case you need to retake your teeth impressions. If your first set hardens too quickly or doesn’t turn out right, this replacement putty gives you a backup so you can still achieve accurate molds for perfectly fitting retainers. What’s Included: 2 base putty packs 2 catalyst putty packs Prepaid return shipping label to send your impressions back to us Having extra putty on hand gives you peace of mind while creating the impressions needed for your new smile. NewSmile 30-Day Fit Guarantee: once you receive your custom-fit appliance, and determine they do not fit within 30-days of delivery, we will send you a new set at no cost to you**terms and conditions apply