The electronic field unit SDR33 by Sokkia

The robust SDR33 was designed for optimal field suitability. Elaborate protection against moisture, dust, and being dropped offered the advantages of intelligent field software even under the harshest conditions. In addition to the expert models with 640 KB, 1 MB, 2 MB, or 4 MB, a basic version with 256 MB was available as well. It offered basic programs for surveying, measuring, and marking.

The SDR33 was sold by GLM Lasermeßtechnik GmbH from 1991 to 2002. Spare parts are no longer available.

The current successor model is the Archer.