Original Deardorff 4 x 4 to 6 x 6 Inch Lens Board Adapter. Nice looking Lens board in very good condition with original Deardorff hardware. Front bottom plate reads: ôL.F. Deardorff & Sons, Inc. Chicago< Illinois, USA. Adapter will fit 4 x 4 Deardorff, Wisner and Zone VI boards. Price: $155.00 shipped in the continental US