Replacement nipple threads into engine block or remote filter head. Overall length is 1 inch. Knurled section 3/8 inch from one end helps to hold the nipple in the filter mount or engine block and prevent it unthreading when the filter is removed.
Note: This nipple has male threads along the entire length to thread into a filter mount. It is not the same as the male-female threaded nipple used with oil filter sandwich plates.