To Test spark plugs performance and ignition strength, apply to 12.0V gasoline car spark plugss. 

Features:
Dual hole car spark plugs tester have two testing holes, you can test two spark plugss meanwhile and and if you suspect any spark plugs works improperly you could compare and test to make accurate judgment.
The could tell the fine spark plugss from the bad by the strength of the spark.
Accurately test the spark plugs performance and ignition strength.
Application : 12.0V gasoline car spark plugss.
and , convenient and easy to use.

Specifications:
Material:
Color: black
Item size: 140 * 77 * 38mm / 5.5 * 3.0 * 1.5in
Item weight: 335g / 11.8ounce
Package size: 170 * 130 * 60mm / 6.7 * 5.1 * 2.4in
Package weight: 380g / 13.4ounce

Packing List:
1 * spark plugs Tester
1 *