Although I was using brass, I bought this here in trouble with rust. There is a sense of cleanliness as it certainly does not rust. Since the lid of a plastic bottle is a consumable item, it may be good to take rust when exchanging on a regular basis, but it is quite troublesome, and if it is to be used for a long time this may be better.
Brass made of the same shape and made of stainless steel The prices are nearly three times different, so we got lost, but we made them stainless steel for long term use for beverages. (It is just a sense of security) Since there are no problems using 3 months, this time it is an additional order. One disadvantage is that the screw is shallow so that when the cap of the plastic bottle is passed through, the engagement of the nut is small, but once it is engaged it can be tightened, so there is no problem.