Suzi, regular rubber bend...these tips are very small, some smaller than a pencil tip size, so rubber band is small enough to secure it tight, the trick is to secure the new tip to the base cutting- or it slides right out. I tried a few nd settled with knotting- I tried a few planting the roots on the new cutting - I don't think those will survive as the joint graft is under the soil... I did a few, where I pulled roots from my big tree and grafted to some either at the bottom or in the half way down the new cutting. Potted 2 and 2 with grafted roots and am nursing 2 in a box, attached to long grafted roots in moss- this will allow me to see if the big roots survived the transplant and if attaches, while the cutting continue its process of rooting. If this works, I will have my tree's cuttings rooting read for new cuttings! Cross my fingers. I will update.