The present invention discloses a pressure cooker cover which comprises a cover and a float valve, wherein a seal ring is installed in the inner edge of the cover while hooks are installed in the two side edges of the cover. Firstly, a first gray level image having a plurality of blocks is received. The planarizing pad material is exposed to a solvent to remove material from one of the first or second portions of the planarizing pad material at a faster rate than removing material from the other of the first and second portions. The illuminated apparatus for assisting movement may be compact and lightweight. The presence of water in the device housing is used to release indicators into the toilet bowl water or into the air.