Making your own Twin sub-woofer/speaker? then you will need professional looking speaker connections to finish the job off. High quality with solder connections on back of each binding post. Solid metal screw down binding posts Removable Gold plated connection strips can be used to equalize the power to both speakers if needed in your setup GOLD PLATED FOR BEST QUALITY Dimensions are as follows: Outer diameter - 95mm/3.8" by 75mm/3.0" (without flange) Depth - 25mm/1" Flange - Sides 10mm/0.4" Top/Bottom 14mm/0.5" Cut hole to 95 X 75mm or 3.7 X 3 Inches to fit plate