Mini Optical Right Angle Prism 90 Degree Square Prism, Double Penta Reflective Surveying Prism for Total Station, GPS Receiver & Theodolite Level
DJ-2 Double Prism Optical Square is used for determining 90° sightings. Comprises of two penta prisms of quality optical glass in sturdy aluminium housing. The accuracy of a right angle set with the optical square is approximately ±1cm at 30m. Used for: placing points on line, setting out curves, offset measurements, determining the horizontal and detail plans.

1. Dual Prism Design for Multidirectional Observation
Featuring two precision prisms, this Double Prism Optical Square supports simultaneous left/right right-angle and straight-ahead viewing. It shows both baseline and perpendicular line at once, no assistant needed—more efficient than single-prism tools.

2. Effortless Right Angle Layout

Easy two-step right angle layout: Hold vertically over the baseline peg (with plumb bob), align two poles' images, then guide a third pole to align—get a precise 90° line for field surveying and marking.

3. Easy Perpendicular Line Setting
Quick perpendicular line setup: Align with two baseline poles, shift to align the target pole, fix position with a plumb bob—no complex calculations, ideal for layout tasks.

4. Durable & Portable for Field Use
Durable optical glass prisms and sturdy housing suit outdoor use. Lightweight with ergonomic grip, compatible with plumb bobs for stable, accurate positioning.

5. Versatile for Professional Applications
Essential for surveyors, engineers and landscapers. Fits right angle marking, curve staking and calibration—reliable for precise 90° measurements in all construction projects.