A memory cartridge system includes a main body, and a main body ROM incorporated in the main body is stored with a warning message display program, and a memory cartridge attachable to or detachable from the main body is stored with a karaoke program. The mechanical connector, having a modifiable length, includes a connector body portion having an anterior side and a posterior side. and pressure of 650 torr that is greater than 400 grams arsine per liter of adsorbent; at least 30% of overall porosity of the adsorbent including slit-shaped pores having a size in a range of from about 0.