One (1) 183 483 Sylvania vintage vacuum tube, ST shape, made in USA. Tube has black ribbed hanging plates, bottom side foil getter. Printed base, tube tests: 98 %. New and shiny in original box. We test all tubes we sell! Check out my other tubes! Tested on Triplett tube tester for shorts and leaks as well. Scale 1-100, good quality percentage on my Triplett starts at 54.