New interpretation of slide rules - LED pendant lamp Abacus Slide rules were used in the past centuries to solve arithmetical problems. It did not matter whether it was a simple addition or more complex formulas. Inspired by this, the Abacus LED pendant luminaire with clear lines was developed to reflect the purity of mathematics. Terzani is an Italian company known for the reinterpretation of traditional materials. Thus, this LED pendant lamp consists of five hand-blown spheres of opal glass, which are attached to a slender brass suspension. Thanks to its subtle design, Abacus can adapt to a wide variety of environments and is suitable for a living room, but can also be used as an elegant light source in the commercial sector. The warm white light of the LEDs gently penetrates the satinised glass, providing uniform illumination with glare-free light.