The Snapwell is a modified Transwell culture insert that contains a 12 mm tissue-culture treated membrane supported by a detachable ring. Once cells are grown to confluence, this ring is placed into either the Vertical or the Horizontal Diffusion Chamber. https://www.ste-mart.com/corni....ng-costar-snapwell-c

Corning® Costar® Snapwell Cell Culture Inserts, Polycarbonate Membrane, TC-treated, CLS3407, Corning, Inc. - STEMart

Corning® Costar® Snapwell Cell Culture Inserts, 12 mm Snapwell Insert with 0.4 μm pore, pore densitiy 1 x 108 pores/cm2.