StacksVerified U.S. regulatory reference

33 CFR §159.65

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
The device must be equipped with one of the following:
  1. (a)A means of indicating the amount in the device of any chemical that is necessary for its effective operation.
  2. (b)A means of indicating when chemicals must be added for the proper continued operation of the device.