the bottom - - over + + means two hands, and - - means the door bolt. Use two hands to pull out the door bolt is Open.
The small seal script for the character is
The clerical script for the character is
The traditional song typeface for the character is
which is very similar to the clerical script.
The simplified song typeface for the character is
which is inside of the traditional song typeface, there is no any relationship with original scripts. It is difficult to understand from this character, so it is a bad simplification.
Its Pinyin is Kai1.