Spectacle frame and headphones: what they have in common

1. Step 1. Spectacle frame — is made of — Bone. The first frames were made of bone and horn.
2. Step 2. Bone — is material for — Bit and bridle. Early cheekpieces were carved from antler and bone.
3. Step 3. Bit and bridle — has part — Headband. Straps on the head.
4. Step 4. Headband — is part of — Headphones. A band that presses the cups.

Open Evothings