220 mm in length, 1/4" Female British Standard Pipe x 1/4" F BSP flare. These are shipped straight and unbent: gently bend with a pipe bender, matching your existing pipe to fit. The flared end goes to the boiler fitting and the pipe end attaches to the pressurestat. If you are unsure it's sorta like this:
WARNING: This product can expose you to chemicals including lead, which are known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information, go to www.p65warnings.ca.gov.