Used for initial exploration of mineral resources, the two-meter-tall Spelunker probe droid had four articulated pincer legs for traveling and a repulsorlift to further support the weight of its cylindrical body.[1] The legs could also generate traction fields, allowing the droid to walk vertically and even upside down.[2] The droid featured bluesensors and copper/gold plating.[1] The mining droids, which were able to survive in a wide range of climates, were dispatched to planets via hyperspace pods, where they would use their sophisticated sensor arrays to locate potential mining spots. Once the droids found an economically viable site, they would begin preliminary blasting in preparation for larger mining teams.[2] Many Spelunker probe droids were later renamed "chameleon droids" and converted into class four droids capable of military service.[1]
The Spelunker probe droid was designed and built by Arakyd Industries, a major manufacturer of droids, heavy weapons, and starships. Shu Mai, the Presidente of the Commerce Guild, a powerful galactic trade organization, bought thousands of them for exploration. Taking advantage of their durability, the Guild used the droids to locate valuable resources on a number of inhospitable planets.[2] However, towards the end of the Separatist Crisis, the Commerce Guild joined the newly formed Confederacy of Independent Systems. The Techno Union, another guild in the Confederacy, took many Spelunker probe droids to be converted for battle.[1] They were fitted with laser cannons,[2] military grade mines,[4] and a holographic array for camouflage. They participated in several battles in the Clone Wars, most notably the Battle of Ilum. All of these units, however, were deactivated after the execution of the Separatist Council at the close of the Clone Wars.[5]
The descendant of the Spelunker probe droid, the chameleon droid, was first seen in Clone Wars Chapter 14, but it was not until the The New Essential Guide to Droids that their origins as the Spelunker were explained.[1] In the English language, a "spelunker" is a person who explores underground areas either professionally or for sport.[6]