Redragon's first ever 100% hot swappable mechanical keyboard! The CASTOR K631 RGB is fully compatible with most 3-pin switches (e.g. Cherry switches) and 5-pin switches (e.g. Mozano eve switches) unlike previous Redragon hot swappable keyboards (e.g. K630W RGB and Deimos K599), which use sleeve style hot-swap sockets. 

 

The CASTOR K631 RGB keyboard uses 5-pin clip style hot-swap sockets, making the CASTOR K631 a true hot swappable switch mechanical keyboard. The CASTOR K631 comes with 3-pin Outemu switches as standard.

The CASTOR K631 keyboard has a total of 68 physical keys (65%), as well as 25 virtual keys that can be accessed via the Fn key command as second functions.Virtual keys include play/pause, next track, Home, Volume and F keys (F1-F12). The list of virtual keys can be found on the user guide along with each Fn command to access them. 

 

As well as virtual keys, you can access lighting settings directly from the CASTOR K631 keyboard too, using the Fn function. You can change lighting effects, adjust brightness, turn off the lighting and adjust speed of lighting effects. The on-board preset lighting effects include 20 in total (no single solid color option support). 

 

If you want solid colors, you could use the Redragon software or use the keyboard's built-in custom light mode but, it involves having to change each key manually which isn't convenient. Another note about the custom light mode is how it is set, which is not correctly described in the user guide. The correct steps are as follows:

 The neat thing about custom light mode is that once saved, the customized lighting effect becomes a preset so, you can access the custom light effect just like the other preset light effects using Fn+PgDn.

On the left side of the CASTOR K631 keyboard, there is a recessed USB-C port and a status led. The recessed USB-C port is tucked inside the keyboard, which is a good design as this will minimize wear on the USB-C port and extend the lifespan of the keyboard. 

 

On the base of the CASTOR K631 keyboard, there are rubberized feet risers for height adjustment. The feet risers do not wobble and have very grippy rubber that prevents the keyboard from sliding off when elevated. With the feet risers extended, the top row of keycaps measures 4.5cm high and the bottom row measures 3cm high. Without the feet risers, the height of the top row is 3.5cm.

Despite the Redragon branding on the switches, the CASTOR K631 stock switches are made by Outemu. The keycaps are made of double shot ABS plastic so, the key legend won't wear off. The dummy switch stabilizers have been lubed with grease so they glide smoothly and provide very little rattling. The actual switches have not been lubed.

The Redragon software application is only available for Windows computers (XP, Vista, Win 7, Win 8 and Win 10) but the keyboard itself is compatible with Mac computers too.  The CASTOR K631 is entirely made of plastic, including the top plate, which helps keep the keyboard very lightweight (437 grams). 

 

The lack of metal plate makes the chassis not as sturdy so, if you're a heavy typist, you will likely experience some keyboard flex. The CASTOR K631 RGB keyboard has no bluetooth functionality. If thast's a feature you want, you can get it with the K530 Draconic hot swappable keyboard

Accessories included with the CASTOR K631 keyboard are a metal switch puller, a metal keycap puller, sticker, velcro strap for cable management and a 2-in-1 USB cable with a with a right angled USB-C plug  and an interchangeable dual plug (USB-A and USB-C). The cable is  made of rubber and measures 1.3 meters long. The CASTOR K631 RGB keyboard is only available in Outemu red switches but, you can get it with a numpad too as a 75% keyboard. You can buy the CASTOR K631 RGB keyboard from Redragon Shop and amazon. Check out the review of the CASTOR K631 PRO,  Elf Pro K649 transparent keyboard, Garen K656 Pro.