Ashe Archery Shot Spot - R. 

High grade laser with the following features, shins up to 1 mile, 2 hour battery life, has a clip to attach to your tree stand and weighs only 10 oz.. Can aid in finding the blood trail simply by shining it on the spot where the deer was standing when you shot, then clip it to your stand, retrieve you game and follow the light back to your stand.