This is a 3-pack of 1/4" Neutrik brand mono phone jacks, with a 9.5mm-long threaded shaft and fastontabs. These jacks are perfect for all sorts of electric guitars, cigar box guitars, and general audio usage. These are not cheap, chintzy jacks that will bend and break with use... these are sturdy, well-made jacks that have been proven tried and true by experienced guitar builders and repairers over the years. Item specifications: Neutrik Part Number: NYS229L Connector Type: Jack Gender: Female Contact Resistance: <10mOhm Dielectric Strength: 0.5kVdc Rated current per contact: 20A Lifetime: >1000 mating cycles Panel Thickness: 6.5mm Contact Plating: SnCe Contacts: Bronze (CuSn6) Insert: Insulation Board Shell: Brass (CuZn39Pb3), gal Ni plated Solderability: Complies with IEC 68-2-20 Temperature Range: -20C to ?? These jacks will accomodate a panel thickness of up to 6.5mm, much thicker than the 3.5mm jacks other suppliers provide.