If you don’t want to add an extra hose to your gear set, you can use a hybrid octopus model. It combines a secondary demand valve and a BC inflation valve. Keep in mind though, that the hose of such hybrid valves is usually shorter.
Even though octopus is not something you will use during your every dive, it can make a real difference in case of an air supply emergency. Therefore, you need to make sure, that the octopus you purchase is of high quality and convenient to use. In addition to a variety of functional secondary demand valves, Dip 'N Dive also carries combination regulators and power-inflators for your Buoyancy Compensator.
To ensure maximum security during the dive, you can also purchase Spare Air (redundant air source), making the system totally independent of the primary air source.