A Swan universal receiver sleeve attached to the top of a firearm upper receiver and extended forward above the firearm barrel to a position just short of the firearm front sight. A method for channel-coding information bits using a code generation matrix including 32 rows and A columns corresponding to length of the information bits includes, channel-coding the information bits having \u201cA\u201d length using basis sequences having 32-bit length corresponding to columns of the code generation matrix, and outputting the channel-coded result as an output sequence. The drive circuit outputs a signal for driving the actuator to eject the ink droplet such that at least three ink droplets are ejected for printing one dot. The reflector is present in the time-of-flight mass spectrometer to generate an electrostatic field permitting the best possible focusing for the deflection of the ions. That is, when the electronic calendar is initialized, no reminders of expired events are visuallyaudibly presented by the electronic calendar.