Wilde Tool Company USA Made Tools #600 Small Engine Valve Spring Compressor Wilde tools are made for the professional who needs toolsthat will last through everyday use for years to come. The Wilde #600 set is for water cooled 4-cycle engines with a springdiameter up to 1 1/16″. The set includes both the large and small Jaws. The set is not for applications with dual springs or Overhead valves that are recessed into the cylinder head.Replacement jaws are available. Please contact us for pricing. Wilde Tool Company also makes this set for Lisle Company, set # 23300. This is a Quality product made by Wilde Tool Company in the USA. Please check out our other Wilde Tools. Questions ? Please email us , we are happy to answer any questions. Thank you for looking.