A gun sling for carrying a rifle or shotgun is adjustable to serve either as a bungee sling or a fixed-length, non-stretch sling. The selected data is displayed on a display. The wide-angle zoom lens system satisfies the following conditions:1. The harness extends from the first housing to the second housing through the first cylinder and the second cylinder of the holder. During the regeneration step, the rate of change in the impedance ratio of the sensor probe to the reference probe is calculated and used to detect two peaks in the rate of change of impedance ratio between the sensor probe and the reference probe, followed by terminating the brineslow rinse step after both peaks have been detected. The network device receives DNS query packet sent by the client, selects a routing strategy from the different predetermined routing strategies, and selects a corresponding WAN interface according to the selected routing strategy.