Let me be 100% clear, I dont know what tonearm this is. I believe this is a Jelco 250 ST tonearm that was sold with an Acoustic Research ES-1 turntable, but I wouldnt stake my reputation on it. If youve seen the photos, you know as much about it as I do. It appears to be in good condition. The lifter is smooth and everything swings freely and smoothly. You can tell it has been mounted before because there are some grub screw marks on the base.This came in a box of turntable parts that I bought. I thought it was a Rega because it came in a Rega RB 300 box, but obviously this is not. It will be packed in the Rega box for shipping. What you see is what you get. You get the tonearm (no cartridge), counterweight, and base. There is no cable. Item is being sold as-is, but other items from the same collection were in excellent condition so I have no reason to doubt it functions normally.