A beautiful matched pair of two (2) NOS NIB RCA 5692 red base/black plate 6SN7GT vacuum tubes in original excellent condition boxes. Superior sound quality preamp tube upgrade for hi-end audio amplifiers. Test as new. Selling AS-IS for parts. Transconductance tested using a calibrated Sencor Continental 150 Tube Tester. Made in USA. Because of their age, these tubes will be sold as is and shipped insured. No International Shipping. Payment due within 24 hours of auction close. NO RETURNS