Audio Research line stage preamplifier in natural (silver). Excellent condition cosmetically with virtually no flaws, perfect condition operationally. The preamp sounds wonderful and quite comparable to my relatively new LS28. The LS25 uses 4 - 6922 tubes in contrast to the LS25MKII which uses 2- 6H30s. Some find the sound of the LS25 preferable, having a warmer, more natural sound compared to the MKII version. Always used in a smoke free enviorment. Original box and packing which are always excellent with Audio Research.