"120/230 VOLTS 50/60 HZ; UTILIZES SPHERICAL PROJECTION TO PROVIDE DIRECT REGISTRATION OF ABSOLUTE TARGET BRIGHTNESS OF 31.5 ASB MAXIMUM AND SPHERE LUMINOSITY OF 1000 ASB MAXIMUM ON A 30 CM RADIUS PROJECTION HEMISPHERE SURFACE; SPRING-BALANCED,CENTER POSTED TABLE,WITH PRECISE BALANCE FOR INSTRUMENT WEIGHT; CONTAINS A TELESCOPE WITH MAGNIFICATION NOT LESS THAN 1.85X; ADJUSTABLE TARGET SIZES OF 64,16,4,1/4 AND 1/16 SQ MM WITH MINIMUM THREE BUILT-IN GRAY FLILTERS HAVING RELATIVE LIGHT INTENSITY LEVELS RANGED FROM 0.0315 TO 1.00; THREE FILTER CAPS ATTACHMENT WITH RED,GREEN AND BLUE COLOR EACH; CHIN ADJUSTMENT RANGE: VERTICALLY-IN EXCESS OF 80 MM"