The grille is available in two variants: H17 or acid-resistant, mounted with straps (PLN 346.86). The area of ​​the openings for the air supply is over 0.022 m2.

According to the Ordinance of the Minister of Infrastructure of April 12, 2002 on technical conditions to be met by buildings and their location. (Journal of Laws of 2002, item 690, as amended, Journal of Laws No. 33 of 2003, item 270, Journal of Laws No. 109 of 2004, item 1156) Chapter 6, §. 79. "The doors to the bathroom, washroom and a separate toilet should open outside the room, subject to § 75 sec. 2, at least 0.8 m and a height of 2 m in the light of the frame, and in the lower part - openings with a total cross-section of not less than 0.022 m2 for air supply ”.