troyscrew - is this what you have?
Brown & Sharpe Hite-Icator - Digital Reading Height Setting and Height Reference Gages
• Accuracy: Within +.000050" (+0.00127 mm)
• Positioning: Rapid adjusting knob for quick, precise positioning of reference blocks
• Micrometer Head: 4" diameter micrometer head for precise, direct reading by .001" (0.002 mm)
• Digital Display: Error-proof .001" (0.01 mm) digital display
• Convenience: Column scales show each 1" (25 mm)
• Efficiency: The top of each reference block is permanently wrung to the bottom of the adjacent block, permitting over and under measurement without changing the setting. Eliminates the need for a reverse checking plate
• Repeatability: Small gaging surfaces designed for ease of use and highest degree of repeatability
• Column: Block column moves as a single unit without rotation
• Lapped Base Pads: Hardened and lapped base pads provide smooth, accurate movement on surface plates
• Extended Work Ranges: Accessory Riser Blocks attach securely to Hite-Icator's base pads by interlocking without clamping. Each Riser Block extends Hite-IcatorÆs working range by 10" (250 mm)
National Supply Source Brown & Sharpe Hite-Icator - Digital Reading Height Setting and Height Reference Gages* - Brown & Sharpe Hite-Icator - Digital Reading Height Setting and Height Reference Gages* Product Page
No affiliation with Nolan Supply; just found this on their website...