Cross reference
1 Kings 7:33
33 The wheels were made like carriage-wheels, the rods on which they were fixed, the parts forming their edges, their rods and the middle points of them, were all formed out of liquid metal.
Ezekiel 1:16
16 The form of the wheels and their work was like a beryl; the four of them had the same form and design, and they were like a wheel inside a wheel.
Ezekiel 1:18
18 And I saw that they had edges, and their edges, even of the four, were full of eyes round about.