These are Gauss woofer kits with functionally and historically accurate Gauss 4583F parts. Where possible, the original spider rings were completely stripped and rebuilt with totally new moving parts including voice coils, spiders and tinsel leads. In other cases we made spider rings out of casting resin and outfitted those will all new terminals (Brass), solder lugs and tinsel leads. We will not use or sell Gauss factory issued parts because Gauss, as a company, closed up shop in 1998 and all of those parts are now nearly 30 years old and cannot be guaranteed for function. These, along with improvements in adhesives, tinsel leads and voice coils will probably do 400 watts RMS and 1.6 kilowatts on peaks, without electrical damage. Shown is a representative voice coil of the "3" or "Extended Bass" series Gauss woofers before we install the second spider. All voice coils manufactured by us for Gauss "4000 Series" or "5000 Series"  speakers will use similar heavy gauge, "high metal content" 12ga tinsel lead and precisely shaped loops to allow for full excursion of the coil while maintaining critical control of the leads themselves. Installation screws are included! Reconing a 4 inch coil Gauss woofer with one of these kits is quite easy! You drop the coil assembly into the gap... center it, tighten it down with 3 screws, test it with a bass frequency signal and, if there is no rub, you tighten down the remaining 3 screws and install the remaining parts! Upcoming kits will be available for following models; 4580/5840, 4581/5841, 4583/5831 and 4583F/5831F. For the older "5000 series" woofers, all we need to do is substitute a voice coil with an Aluminum former instead of Kapton and your functionally and historically accurate rebuild will be complete! If you have a model Gauss woofer not included here, send us a picture in "contact seller" and we'll tell you what kit you need for it. The 4582/5842 models are still being engineered. As of this listing I have 8 kits. ONLY UNINSTALLED, UNDAMAGED VOICE COILS WITH NO ADHESIVE ON THEM ARE RETURNABLE! The discount shipping rate is for continental US addresses only. All others are actual cost! Thank you for checking out my listing! PEACE!