Phoenix Contact Insulated Bootlace Wire Ferrules, AI Series. A range of insulated bootlace wire ferrules made from soft tin plated electrolytic copper with a polypropylene insulating sleeve with a colour range that conforms to DIN 46228-4: 1990-09. These insulated bootlace wire ferrules are available with twin wire entries enabling two conductors to be crimped in one ferrule. Stock number ; 804-6925 804-6925 has an increased insulating collar diameter for conductors with increased insulation For suitable hand crimp tools see stock numbers ; 803-4405 803-4405 , ; 803-4427 803-4427 , ; 803-4411 803-4411 ; ; 803-4420 803-4420 typically