Lancets-Tenderfoot. The Tenderfoot lancet is a fully automated heel incision device that provides a simple and effective way of collecting blood samples from newborns and toddlers. These are single use devices and provide an incision 1.0mm deep and 2.5mm in length. Questions Or Problems?Send us an Email.© 2013 BirthWithLove Midwifery Supplies. All Rights Reserved.