I have had this one for the past four years and no problems.
[ame=http://www.amazon.com/Electronic-Specialties-325-Automotive-Tachometer/dp/B000UZO0L0/ref=sr_1_8?ie=UTF8&qid=1366397448&sr=8-8&keywords=handheld+tachometer]Electronic Specialties 325 EZ-Tach Digital Automotive Tachometer : Amazon.com : Automotive[/ame]