According to Delta, all of their shower doors feature 1/4" or 3/8" frameless tempered glass panels. Frameless doors are easier to clean than framed doors and provide an aesthetically pleasing look that enhances any bathroom by creating a more spacious feel. Framed doors offered by most manufacturers have an aluminum frame around each glass panel. Semi-frameless doors have aluminum top and bottom tracks and thicker metal side pieces paired with frameless glass giving it a blended look that's open and spacious but trimmed and finished.