creating table syntax error

I have a problem creating the table. It says unexpected parenthesis at line 3

create database scl_teachers;

use scl_teachers;

create table clteacher (

'id' int (10) primary key auto_increment ,

'f_name' varchar(255) not null,

'mid_initials' (255) is null,

'l_name' varchar(255) not null,

'saturation' varchar (2)

);