Abacus® Frame and Parts

  • Frame dimensions – 13 7/8” long x 6 5/6” wide x 2” tall
  • Stainless Steel catch rail trigger – locks axles in place
  • Axle slots
    • 6 on the front face of the Abacus® frame
    • 5 on the back of the Abacus® frame
      • The Abacus® slots are numbered and also have Braille designations for the blind.
  • Balls w/hub (4 total)
    • One Burgundy 52mm – 24 durometer (Shore 00-24)
    • Two Lime Green 52mm - 40 durometer (Shore 00-40)
    • One Blue 52mm - 55 durometer (Shore 00-55)
  • Spacers (6 total included)
  • Axle (3 included included)
  • End caps (6 included included)

Ball Assemblies

The ball assembly can be configured using multiple combinations, with one or two balls per assembly. The end caps can be removed for the various balls and spacers to be installed. The balls, made from a proprietary Gelliprene™ material, are manufactured with a 52mm diameter in 3 different durometers (or firmness). The burgundy ball is the softest, the 2 lime green balls are medium firm, and the blue ball is the hardest firmness.

 Diameter Durometer
52 mm 00-24 Shore
52mm 00-40 Shore
52 mm 00-50 Shore


Arm Size Limitations: The compression function of the Abacus® is designed to accommodate an arm (forearm or upper arm) with a diameter of up to approximately 4.5”. An arm or portion of an arm with a diameter in excess of 4.5” will likely not be able to take advantage of the compression function. The other functions (rolling and squeezing) will function with larger arms.