K&E slide rule with scales, each with engraved markings. All manufactured markings are clear. The body is the original ivory color with no discernable staining, fading or blemishes on the scale. The top and bottom scales are fixed in place; the center scale slides right or left to perform a calculation. There is a clear plastic window with a center line that is used to read out the result of the calculation. Markings are located on both sides of the slide rule for different types of calculations.
The center scale slides right and left freely if the slide rule is held by the metal end fastener. If the slide rule is held in the middle, squeezing the top and bottom scale, the center slide is locked in place and will not move. This function was designed to prevent losing the result of a calculation by accidently moving the slide.