A single Preview Crate: New Moon was a possible reward as part of the September 2019 daily rewards, given for logging in for 21 days that month. Unlike regular New Moon crates, the Preview Crate pulls from a limited pool of potential rewards. They can be distinguished from regular New Moon crates by their blue color, as opposed to the usual green.
Notably, these crates are guaranteed to grant one of five pets modeled after the Apex-level mounts of the New Moon Season released the following month. The pets found in the preview crates are not available in regular New Moon Crates.
The possible rewards are as follows, grouped by rarity with Legendary rewards being the rarest:
Duplicate Legendary rewards grant from extraction.33
Unwanted Fine Rewards grant from extraction.1
Unwanted Common Rewards grant from extraction.1