Mechanical Installation 2.213Common Mounting PrinciplesTips Select flush mounting where possible to make your product elegantlooking, more vandal resistant and more secure. You can purchase the flush mounting box in advance and hire aninstallation professional to make the basic installation work. Moreover, themounting box helps you align the intercom vertically (with a deviation ofup to 2°).Caution Make sure that the dowel holes have the required diameter. If thediameter is too large, the dowels may get loose. Use some suitablebuilding adhesive to keep the dowels in place. Make sure that the hole depth is sufficient too! The dowel length is 50 mmand the screw length is 90 mm. Remember that dowels of poor quality may easily get loose and fall out ofthe wall! Stainless steel screws are used for the 2N® Helios Force / Safetyassembly. Other screws than stainless steel ones corrode soon and mayaesthetically deteriorate the surrounding environment! Having removed the front panel, make sure that no dirt gets inside theproduct (especially onto the sealing surface and microphone soundguides).Note The microphone sound guides are normally loose after the front panel isremoved! The screw is only used as a fall-out protection duringinstallation.