This is a Classic Instruments ?White Hot Series? universal tach, brand new in box, five-year warranty. It is 3 3/8 in diameter and comes with all mounting hardware and instructions for in-dash mounting. Part Number WH80SLC. I bought the wrong one on ebay from a vender that neglected to include the diameter of the tach on its ad & then wouldn?t cancel the order. My loss is your gain. Paid $130, sell for $105 plus shipping.