Gold plated binding posts are ideal for demanding speaker enclosure applications where thick walls prohibit the use of conventional cup terminals. Extended thread length is perfect for enclosures of up to 1" thick. To install, simply drill a 1/4" hole, and tap the post into place from the outside. The knurled shaft creates an airtight fit and will not rotate. External connection features a 8.5mm diameter post which acccepts spade lugs, bare wire up to 8AWG or banana plugs. Internal connections are solder lugs. Sold in pairs, color coded red and black.