Superior Labs 3 1/8" Mooney Mechanical Tachometer SL1010-44006-13-N00. Superior Labs (SLI) is the aircraft tachometer of choice by many OEM’s due to its precision and reliability. The Superior Labs 3 1/8" Mooney Mechanical Tachometer SL1010-44006-13-N00 has a Green ARC of 1950-2500/2500-2700, a Red Line of 2700 and records at 2500. SLI also offers precision aircraft tachometers for aftermarket replacement for most single engine aircraft. SLI manufactures aircraft tachometers for all general aviation aircraft types and offers custom screen printed dials, internal lighting, anti-glare glass, and pre-set engine hours. This specific unit replaces Mooney M20 Models.