(piston) ring

(semi-)prime ring

(stong) regular ring

0-ring

1 550 nm fiber-optic ring network

10 kV ring

10 kV ring main unit

10-membered ring hydrogen bond

13-membered ring hydrogen bond

14-membered ring

170-millimeter-thick ring plate

18-18 steel for retaining ring

18-5 steel for retaining ring

20mA current ring

250B bearing ring rolling machine

Ⅱ-coherent ring

33 matrix ring

4-Ring

500 kV main ring network

5-membered ring hydrogen bond