Here is a nice group of glass radio antenna (strain) insulators.

Left to Right

1. Pyrex / Made in USA on front. A6 / Pat 1700066 on the back. Crystal clear. 3.6" long, 1.13" diameter. Ground end, perfect condition. $4 US plus shipping. SOLD

2 Knox / Knox embossed on one end. Crystal clear. 3.2" long, 1" diameter. Ground end, perfect condition. $4 US plus shipping.

3. No embossing, light straw fat boy. 3.6" long, 1.25" diameter. Ground side of eye, .5" chip on top rib in picture. Displays mint from the other side. $3 US plus shipping.

4. No embossing, light straw. 3.8" long, 1.37" diameter. Ground side of eye, .25" chip on top rib in picture. Tiny chip on next rib. Displays mint from the other side. $3 US plus shipping.

Shipping is from Canada. Take all three remaining for $8 US plus shipping. I take PayPal.