The Mini Isotopes come in a choice of seven different colours so that you can match them to your bite indicators. They have been designed to fit in the top of the Distance Sticks, as well as the Black&Whites bobbins and Stow indicators – they are 15mm long with a 3mm diameter. These isotopes are high powered and of a high quality, as well as being extremely long lasting. They come in a choice of green, yellow, red, blue, purple, white, or orange. You get one Mini Isotope per pack.