The terminals are covered in black boots that protect the conductor from engine heat to ensure spark delivery.

The Street Fire Spark Plug Wires feature a low resistance conductor that's wrapped in a sleek and durable black sleeve.

Helically wound conductor suppresses electro and radio noise
Kevlar core combination for great strength and durability
Heavy Duty Terminals For Secure Connection
8mm silicone and synthetic jacket resists heat and abrasion
500 Ohms/ft. Resistance For Improved Spark Delivery And Power
Silicone Boots Protect Against High Exhaust Temps

Information:

Holley Performance Emission Code 5: This part is legal for sale or use on Emissions Controlled Vehicles; Uncontrolled (Non-Emissions Controlled) Vehicles; and Racing Use Only Vehicles because it does not affect vehicle emissions and is not covered by emissions regulations

Application Summary:

Year	Make/Model
1960-1967	American Motors Ambassador
1963-1966	American Motors Classic
1965-1966	American Motors Marlin
1960-1961	American Motors Rebel
1973-1975	Buick Apollo
1971-1973	Buick Centurion
1973-1977	Buick Century
1979-1981	Buick Century
1991	Buick Commercial Chassis
1960-1980	Buick Electra
1970-1979	Buick Estate Wagon
1965-1967	Buick Gran Sport
1970-1972	Buick GS
1968-1969	Buick GS 350
1968-1969	Buick GS 400
1970-1972	Buick GS 455
1960-1963	Buick Invicta
1960-1975	Buick LeSabre
1977-1979	Buick LeSabre
1973-1977	Buick Regal
1979-1981	Buick Regal
1963-1974	Buick Riviera
1977-1978	Buick Riviera
1991	Buick Roadmaster
1961-1972	Buick Skylark
1975-1978	Buick Skylark
1961-1969	Buick Special
1964-1972	Buick Sportwagon
1963-1970	Buick Wildcat
1993	Cadillac 60 Special
1987-1993	Cadillac Allante
1987-1992	Cadillac Brougham
1965-1976	Cadillac Calais
1975-1989	Cadillac Commercial Chassis
1991-1993	Cadillac Commercial Chassis
1960-1980	Cadillac DeVille
1982-1989	Cadillac DeVille
1991-1999	Cadillac DeVille
1960-1978	Cadillac Eldorado
1980-1989	Cadillac Eldorado
1991-1999	Cadillac Eldorado
1999-2000	Cadillac Escalade
1965-1980	Cadillac Fleetwood
1982-1989	Cadillac Fleetwood
1991-1992	Cadillac Fleetwood
1960-1964	Cadillac Series 60 Fleetwood
1960-1964	Cadillac Series 62
1960-1964	Cadillac Series 75 Fleetwood
1980-1989	Cadillac Seville
1991-1999	Cadillac Seville
1961	Chevrolet Bel Air
1961	Chevrolet Biscayne
1961	Chevrolet C20 Pickup
1961	Chevrolet C30 Pickup
1961	Chevrolet Impala
1961	Chevrolet K20 Pickup
1961	Chevrolet Suburban
1960	Chevrolet Truck
1960-1971	Chrysler 300
1975-1983	Chrysler Cordoba
1983-1989	Chrysler Fifth Avenue
1960-1975	Chrysler Imperial
1981-1983	Chrysler Imperial
1977-1981	Chrysler LeBaron
1960-1982	Chrysler New Yorker
1960-1981	Chrysler Newport
1960	Chrysler Saratoga
1960-1981	Chrysler Town & Country
1960-1961	Chrysler Windsor
1963-1964	Dodge 330
1963-1964	Dodge 440
1962-1965	Dodge 880

Attributes
ASIN	B001BDSVOM
Boot Material	Silicone
Boot Type	Multi-Angle
Brand	MSD
California Proposition 65	WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov
Category	Ignition, Ignition
Color	Black, Black
Core	Copper
Country of Origin (Primary)	MX
Emission Code	5, 5
Engine	Universal 8 Cylinder
Engine Make/Size	Universal 8 Cylinder
GTIN	00085132055517
Harmonized Tariff Code (Schedule B)	8544300000
Hazardous Material Code	N
Insulation Color	black
Life Cycle Status Code	Available to Order
NAFTA Preference Criterion Code	B
Position	N/A
Product Type	Spark Plug Wire Set
SDR Required Flag	N
Series	Street Fire Spark Plug Wires
Spark Plug Boot Angle	90°
Sub Category	Ignition Wire and Related Components
Subcategory	Spark Plug Wires
Warning	California Proposition 65
Warranty Time	12
Wire Diameter	8
part type	Spark Plug Wire Set