The phrase "metal ones" refers to objects or things that are made of metal.
Sentences with «metal ones»
The wardrobe is given a new lease of life by painting it white and replacing the handles with metal ones. (idealhome.co.uk)
I use silicone mini loaf molds, if you are using metal ones, butter and dust with flour, or line with parchment. (thebakingskillet.com)
The plastic kitchen pulls were replaced with new black metal ones and some simple sea fan prints give the broken wall a sense of continuity. (thepaintedhive.net)