Black markings on yellow, with red stud center markings every 16
inches.

Measurements are marked on both sides and both edges, graduated to 1/16th
inch.

Engraved graduations on both sides.

Constructed of tough nylon, reinforced with glass fibers for added
durability, and resistance to weather, abrasion, and most
chemicals.

Positive locking joints and stainless steel spring hinges for added
strength.