The JJ-CCR is a multi-gas, closed circuit rebreather sold in more than 3000 units. It is commonly called the 4×4 by the technical rebreather community which in many ways is the perfect description as it is built for all types of terrain and can be adapted to handle the most demanding diving operations. It is today one of the absolute most used rebreathers within advanced cave and wreck diving. The environment the JJ-CCR was built for demands a rebreather that is simple and sturdy in regards to handling and ruggedness, independent of the situation and operational environment. All of the components of the JJ-CCR have been carefully selected and are there for a reason! Each detail has a purpose and every solution can be justified.
The development of the MURO-CCR was initiated by a request from the Nordic defence environment in 2015 and was further boosted when a NATO-diving unit came with a direct request of a non-mag version of the JJ-CCR in 2018. The JJ-CCR have been used as an evaluation platform for a number of European defence dive units since 2015 and feedback from some of these units have provided valuable information to the project. The most significant feedback was that the standard JJ-CCR unit worked perfect from a piloting and safety perspective, so for us it was the signature in terms of magnetic and acoustic properties that needed to be solved.
