This is a custom-made, adjustable slide receiver for a trumpet. It's a heavy-duty type, with the body made of a "double-walled pipe" construction, using a brass tube with a copper tube layered inside. The second photo compares it to the regular type; this item is on the right. Photos 3 and later show examples of it attached to a trumpet. It can be attached within this range, and the bell direction is limited by the existing slide receiver, as shown in photo 4. The instrument itself is not included in the sale. It's assembled with all new parts, but it was installed and photographed for inspection before listing, so it's not strictly unused. Tightening the nuts in tight spaces can be difficult, but please refrain from using tools like needle-nose pliers. Excessive torque can dent the tubing. Tighten them patiently by hand.