25B302 up for sale is a used older Hansen Synchron rectangle 4 hole mount drive unit, the motor is marked 36 RPM but this unit is geared down and the shaft only turns one revolution in 1 minute and 40 seconds . So this shaft turns 36.14 revolutions per hour , the units rectangle area is 3 1/4 x 2 1/4 the 4 mount tabs with holes extend out from the 2 1/4 area by 3/8 on each side , standard mounting pattern for this synchron movement , the shaft that comes out the front is 0.170 inch outer diameter with a set screw flat this flat measures 0.137 from the back of the round to the flat surface , the shaft extends 0.885 from the face and near the base of the shaft it gets bigger for about 0.200 inch , the total height of the unit including the shaft is 2.810 . The shaft turns CW looking from the shaft side down , nice older drive unit for many applications, see our store we try to add new items like this each week to our store here on ebay , thank you rwk