Vintage 3.5" Clear Glass Armstrong 21 55 Insulator Made in USA

Vintage 3.5" Clear Glass Armstrong 21 55 Insulator Made in USA. No chips that I can feel or cracks. Could use a more detailed cleaning. Photos are an important part of the description. Measures approximately: Height 3.5" Width 2.5" Has what looks like a zinc liner where it screwed on Features: • 21 55 Size: 3.5" Condition: Pre-Owned Good