Update December 22: Valve changed its Steam store listings for all Valve Index hardware to “notify me”, effectively removing the ability to pre-purchase the system after the headset was backordered to February. Original story follows that was first published on December 14.

Time may be running out to purchase a full Valve Index VR kit and have it arrive before the launch of highly anticipated game Half-Life: Alyx.

New orders of the $1,000 Valve Index VR kit “will ship in February 2020,” according to the Steam store, “due to recent high demand” following the reveal of the full VR game in the iconic franchise set between the events of Half-Life 1 and Half-Life 2. Just a few days ago the high quality VR system was backordered to January after shipments of new orders pushed past Christmas at the start of the month.

We confirmed with Valve the forthcoming VR game includes some optional interactions that only work with the Index controllers which come as part of its VR kit, and the game is slated to arrive in March 2020 for all Steam-compatible PC VR headsets.

Half-Life: Alyx will work with all PC VR headsets with tracked hand controllers but, in addition to optional interactions like crushing cans, some things “end up being better on Index Controllers because we were developing them in concert with the game,” according to Valve. Index controllers differ from other hand controllers, like the HTC Vive wands or Oculus Touch, because they strap to your hand and allow you to fully release your grip.

In case you haven’t seen it, or just need to see it again, below is the trailer for Half-Life: Alyx.

Index is a modular system which relies on SteamVR Tracking base stations to track both headsets and controllers. It is an evolution of the system Valve partnered with HTC to ship back in 2016 and components like the Index headset and Index controllers can be purchased piecemeal as individual upgrades to the original HTC Vive. Those pieces, though, are shown as out of stock on Steam.

The Index system is only officially sold through Valve’s Steam storefront, so any listings you find on other sites like Amazon are likely coming from resellers looking to markup the price.

Half-Life: Alyx will sell for $60 but it is bundled free for people who have the Index Controllers or headset, and there’s a pre-purchase discount for the game as of this writing. While new buyers of the Index kit won’t expect shipments until February and Half-Life: Alyx is slated for release in March, we should of course note the concept of “Valve Time” that could upend expectations set for either Valve software or hardware.