Apparatus is configured for producing an output signal indicating an operating status of a monitored circuit. Implementations may include billing server configured to calculate the security protection consumed by calculating damages avoided from attacks that were blocked. The removable hitch attachment further includes an edge engaging structure configured to receive one of the edges of the bucket to secure the hitch mount to the bucket. The optical amplification is an amplification method in which the signal light and light of pump light are introduced into a rare-earth doped fiber, a stimulated emission is caused, and the signal light is amplified. A head bag with the height of 2 cm 4 cm is sewed to the upper section to oppose upward to the bottom bag The number of the upper section is not limited to one, but the upper section with the width of 2 cm 3 cm can be provided above both sides of the lower section. , to transfer data from the implant andor to receive instructions for controlling the implant.