The submarines carry the Thales Underwater Systems Type 2054 composite sonar. The Type 2054 is a multi-mode, multi-frequency system, which incorporates the 2046, 2043 and 2082 sonars. The Type 2043 is a hull-mounted active/passive search sonar, the Type 2082 a passive intercept and ranging sonar, and the Type 2046 a towed array sonar operating at very low frequency providing a passive search capability. The fleet is in the process of having the sonars refitted to include open-architecture processing using commercial off-the-shelf technology. Navigational search capability is provided by a Type 1007 I-band navigation radar. They will also be fitted with the new Common Combat System. Two periscopes are carried, a CK51 search model and a CH91 attack model. Both have TV and thermal imaging cameras in addition to conventional optics.