The OnePlus One smartphone by OnePlus will finally be available to the public via pre-order today at 3PM GMT but there's a catch: you'll only have a one-hour time window.

OnePlus One unveiled in April, with a starting price of $299 for the 16GB model. Because the smartphone features a range of impressive specifications, an open source operating system, and an relatively cheap price tag, OnePlus has been running into scaling issues. OnePlus One still isn't available for purchase, for instance, but has been available through an invite-only system.

READ: OnePlus One review

The company recently confirmed however that its invitation system would end in October. An executive at OnePlus announced through a Reddit AskMeAnything thread that OnePlus One would be available for pre-order "soon". We now know pre-orders will open today, 27 October, at 3 PM GMT but you will only have till 4PM to get your order in.

"If a coveted invite for the OnePlus One always seems to elude you, we think you will be thrilled by a different kind of invitation we are offering. We would like for you to be a part of the first monumental change to OnePlus - the new pre-order system," explained OnePlus in a blog post. "While the pre-order system won’t completely replace the current invites method, it is certainly a huge step towards expanding the reach of OnePlus."

In addition, OnePlus said all accessories will be sold at "celebratory sale prices when added to your order". It is selling JBL E1+ Earphones, for instance, at a discounted sale price of $24.99, but only until the pre-order window ends.

Visit OnePlus One's pre-order page to place your pre-order.

READ: It's official: OnePlus 2 is in the works - what do you want it to have?