This is an antique Aladdin No. 23 oil lamp burner with mantle holder. It looks to have 2" threads and appears totally functional. I will be selling a lot more crystal pieces and prisms. I purchased an estate from a well known lamp collector. There were dozens of high end lamps and thousands of parts and pieces, including thousands of prisms and assorted crystals. I will be listing them over the next days and weeks so be sure to check to see what else I list.