Lightly used spark tester for 1 to 8 cylinder engines.  I sold both my boats so I no longer need this item.  Both engines were from the 80's so there was often problems.  This tool came in handy many times during trouble shooting.  It works as it should and again it is lightly used.  Save a few bucks and purchase a quality used item. 

cdi Electronics 511-9766 : Enclosed 8 cylinder adjustable spark gap tester. Has heavy-duty wire for mounting in any position. Helps reduce possibility of igniting gas fumes.