Bullet Resistant “C” Channel Transaction Window Frames are made from 12ga. stainless steel and formed into “C” channel at jambs. Stainless steel caps are welded to frame jambs to form head and sill frame caps. The window is factory glazed with natural voice setting blocks to all natural voice transmission through frames around glazing. “C” Channel windows are available with laminate or stainless steel counters and can also be made to install on existing counters.