For out-of-stock items, we post an ETA date provided by our supplier, or else we adjust it conservatively to be on the safer side. We hate stockouts and work to stay on top of the situation with the source, to ensure that our information stays current. In all likelihood, we probably get called pests (and worse) by manufacturers and suppliers who've run out of things. For many of the products WaterCheck.biz offers, we know from manufacturers that we carry a larger stock of their product as a percentage of sales than any retailer in the world, and we reorder long before counts hit zero. This means that by the time we’re out of something, most others usually have been out for some time. It also means that the way you’re most likely to get the item the soonest, is to preorder with us. In some cases, preordering can even prevent having to wait until a second new shipment comes in, before unspoken-for stock becomes available. ETA’s from our suppliers are usually quite accurate. But things can happen, from shipping damage to lost cargoes to customs delays, so it’s important to remember that the "E" in “ETA” stands for “estimated,” not for "exact." Our pledge is two-fold: To provide the most accurate information possible, and to get stockout items back out the door again very quickly once they arrive.