A gas meter is mounted between vertical and horizontal branch tubes of a gas canister valve and has an indication pointer driven by a magnetic block that is movable inside the valve to indicate a residual quantity of gas inside the canister. The network behavior of users of a computer-implemented social network are observed and used for user profiling. The annular body has multiple sections that include a first section and an opposite second section. The optoelectronic device is disabled and a count of compared bit groups is kept until the comparison indicates that the optoelectronic device is completely off.