Anyone knows what it is?
A shut off valve.
It could be several things.
Non softened water line for drinking.
Line to reverse osmosis drinking water system that has been removed.
If it’s hot it could be for a dishwasher.
1/4" Ice maker
Like Mr. Larson said it could be alot of things. Stub in for a dishwasher, filtered water system, seperate spray faucet depending on the sink type.:shock:
Around here it is common for an exterior hose bib.
Common here also for exterior faucet. Typical for a slab on grade configuration.
Upgraded the kitchen and needed to cover over this older spigot shut-off.
I shut mine off during the winter (and open exterior faucet) to keep exterior bib from freezing. Many homes have hose bib shut-offs under the kitchen sink and under a bathroom sink.