What it means
The Australian Consumer Law guarantees that goods are reasonably fit for any particular purpose the consumer made known to the seller, either directly or by implication, before buying. It also covers any purpose the seller represents the goods are suitable for. If the goods can't do that disclosed job, there is a failure of a consumer guarantee and the consumer is entitled to a remedy. Like other guarantees, it cannot be signed away.
How it's used
A customer who tells staff they need waterproof boots for hiking can claim a remedy if the boots leak on the first walk.