The same binding posts we use in our Mercury Speaker Kits.
Product Description from Dayton:
These heavy-duty binding posts were designed with the audiophile in mind. Quality, 24kt. gold plating assures the highest possible signal transfer and resists harsh environmental corrosion. The binding posts can be used with banana plugs or will accept wire up to 8 gauge. The large diameter knurled head allows for positive finger tight connections. Extra long rear bolt (1-1/2") for mounting in speaker cabinets with walls up to 1" thick. To install, simply drill a 1/4" hole and gently tap the binding post in place. The knurled shaft will keep the post from turning and creates an air-tight fit. Overall length is 2-1/4".
Sold in colour coded pairs (1x red and 1x black). Ie enough for one speaker. If you are building a pair of speakers, you will need to purchase 2x sets.