Electra Gear Speedtronics EL-HM-830-20-H1 Gearbox 20:1 Ratio 180TC Hollow Shaft

Gearbox has a hollow shaft fitted with an 1-1/2" dia x 4" output shaft.   
Electra Grove Gear EL Series EL-HM-830.
Gearbox is without the original tag.  New condition.