do exactly what it says on the tin

From the sense of tin meaning a can, originally the slogan of an HHCL advertising campaign of UK television commercials for Ronseal Quick-Drying Woodseal.

• "So if you've got wood to stain and you want it to dry quickly, use Ronseal Quick-Drying Woodstain. It does exactly what it says on the tin."
• "[The Erotic Art Museum] does exactly what it says on the tin: presents erotic art […]"
• "“That update is doing exactly what it says on the tin,” Jack started, demonstrating the date of birth restriction. It only returned the day and month now, holding back the year, causing some of Jack's regression tests to fail."
• ""Until we get a train that performs to specification, it's difficult to put a timeline on it. The train does not do what it says on the tin."
• "The solutions to this crisis are clear. We must keep fossil fuels in the ground and deliver a clean, green and affordable energy system. We need publicly owned utilities to do what they say on the tin, rather than simply siphon off obscene profits to shareholders."

• what you see is what you get

• Ronseal