Superb value for money specialist isotopes. Pack contains two isotopes and 14 various sized rod top adaptors. The selection of green adaptors fit a wide range of quiver tips and rod tops providing a neat attachment system and acting as a sight bob. Isotope colour is green as this has proved to be the most effective and brightest of all the isotope colours. For best results put a pair of isotopes aligned on the rod tip about 25-30cm apart, bites are much easier to read as the twin lights move apart.