SCIO ruler is a rotating device composed of two disks. Upper disk is marked with 5 SCIO cretiria to select (clinical form, depth of involvement, hyperkeratosis degree, age and location). On the lower disk all corresponding SCIO values are present. Reverse contains treatment guideline for resulting ranges of SCIO.

Using SCIO ruler is easy, just rotate the disk and get the result.
Many physicians in Russia and abroad are familiar with SCIO ruler an use it now evaluating and treating patients. SCIO ruler is also used in all SCIO-related studies.

SCIO ruler was printed in 5 editions, each containing modification (about 30000 pieces printed in total). Recent modifications, in addition to improved design, contain color scheme for different treatment approaches (e.g. topical treatment is green and nail avulsion is red). These newer rulers even contain a hole (incision) to measure nail length and involvement.