For cycling and cross training. CS300 is the optimum choice for a fitness cyclist who also enjoys other cardio sports. You can easily wear your CS300 wrist unit during the indoorfitness session or mount it onto your bike when cycling. With CS300, the proven, excellent polarpersonaltrainer.com online training programs are at your service. The new CS300 is a wrist unit with powerful cycling featuresand cross training functionality. CS300 is tailored to fitness cyclists and cross trainers eager to stay in shape and up their fitness levels. CS300 has a new service free Speed sensor and optional Cadence sensor. CS300 is water resistant, so you can also use it in the pool.