The Car Subwoofer  Type VOICE COIL
4'' Size Coil
The BLACK ALUMINIUM Bobbin Material, Short for BASV, quite good heat dissipation nature
The Taping Paper is White Spunlace Cloth
The Aluminium Ribbon Wire as Winding Wire, with heat Resistance Glue Varnish
The Edgewound Winding Method
Widely Used in HIGH POWER Car Super Subwoofer.