Had received 4-pcs of Diffusers out of them 3 had the corners broke when the package was open, took pictures of the damage sent them to 1800 ceiling. I had received an email back immediately from them saying to keep the filters and throw out the 3 bad Diffusers and new ones were shipped to me immediately the same day and they had followed up the same day. This is probably the best service that have ever had from any supplier would recommend them always Thanks