The Foba STAPI Telescopic Extension is an integral part of the Combitube system.It extends from 37.4" - 7.6"With the female Combitube connector at the bottom, the 3 section upright can be used with other Combitube sections for additional heightIt comes with a fixture adapter and an additional 3/8" threadThe lower tube of this Foba combitube system is equipped with a shock-absorbing springThe STAPI is compatible with CESRO, STARE, and CESRA bases