It depends. It may be that we are making more kits or it may be that we are waiting on a delivery to arrive to us. Typically, a back order is filled in under two weeks. If it is longer, we will notify you via email with an expected ship date. (Some back orders can take several months.)
If we are able to ship part of your order, we will do so. We will also include a note in your order letting you know the expected ship date of back ordered items.