Falcon™ 12-Well culture companion plates are made of tissue culture treated polystyrene and are intended for use with cell culture inserts. They have wells with specially designed notches that hold the insert in place which allows for pipetting in to the well. The notches also provide a tight fit for the lids. The labyrinth design of the lids and condensation rings minimize the possibility of contamination or evaporation. Sterile plate trays are peel-open and individually packaged. Case of 50. Falcon® (a Corning Brand) #: 353503.