NTI Audio › NTI XL2 Analyzer and M4261 Class 2 Measurement Microphone - Rechargeable Li-ion Battery Image 1 of 1 NTI XL2 Analyzer and M4261 Class 2 Measurement Microphone - Rechargeable Li-ion Battery $2,464.00 Get notified by email when this product is in stock. Quantity: Add To Cart Added!