For sale one Have 4 in stock Black inside not gray Pre 1950s tubes here Vintage CBS Hytron 5814A vacuum tube. • Made in USA • Equivalent to 12AU7 • Military/industrial grade tube • Orange print, vintage production • Appears NOS • Clean pins, no visible damage • Untested – no tube tester available Highly regarded for audio and vintage equipment use. Sold as-is, untested, no returns. US mainland shipping only.