The easy to use GladGirl Natural Lash Ruler is a clear see-through plastic lash ruler that makes measuring your client’s natural lashes simple and easy. Be sure you have your client’s lash length in mind when picking the perfect set of dreamy lashes that they will love! Pro Tip: To help keep the natural lash in prime health, as well as get the best retention rates, be sure to use the proper length of extensions. A good rule of thumb to follow is to not go over 2 mm in length above the natural lash length. You can determine natural lash length by simply measuring the lashes prior to the start of your full set to determine that length tray you should reach for.