full set with 16 cards for testing of infants (6 months to 3 years), low vision or disabled adults - the TAC set includes a Blank and gratings from .23 to 26.0 cpcm - graded gratings: 20/30, 20/40, 20/60, 20/80, 20/100, 20/150, 20/200, 20/300, 20/400, 20/600, 20/800, 20/1200, 20/1600, 20/2400, 20/3200 equivalent to VA decimal: 0.66, 0.50, 0.33, 0.25, 0.20, 0.13, 0.10, 0.060, 0.050, 0.030, 0.025, 0.016, 0.0125, 0.0083, 0.00625 - all cards measure approximately 25.5 x 55.5 cm (10 x 22 inches) - a manual is included with each set