In this livestream episode by Patrol Base, they talk about the APS Phantom Extremis Mark X AEG that is available at their store... "Introducing the Phantom Extremis Mark X AEG by APS. This AEG is the latest in a long line of 'PER' AEGs from APS, and is absolutely jam-packed with performance-enhancing features which will have you dominating the local CQB sites, whilst retaining compatibility with AR15/M4 STANAG magazines and keeping the good parts of the AR15 look and ergonomics.

Starting at the front of the rifle we have a 'vortex' style flash hider that mounts to the 14mm CCW male threads at the tip of the alloy outer barrel. The rifle features a short M-LOK handguard with 8 mounting surfaces, meaning you can add what you need for your mission wherever you want. There is a small section of Picatinny rail at the front 12 o'clock position of the handguard, providing a position to mount the included green fibre optic front sight. The handguard meets the receiver in a monolithic fashion, keeping the sleek looks of a free-floated AR15 handguard and avoiding the extra weight of a delta ring style handguard attachment system.

The changes APS have made to the standard AR15 receiver are extensive. Both the upper and lower receiver includes lightening grooves to keep the weight down whilst adding to the modernised AR15 aesthetics. Also present on the lower receiver are enlarged controls, including an ambidextrous fire selector and magazine catch. The markings on the fire selector read "hold" "pain" and "hell", adding a unique and humorous aspect to this killer of an AEG. The forward assist, usually found on the right side of an AR15 behind the ejection port has been deleted from this AEG in order to keep the weight low, a common practice in real-world modernized ARs.  In its place we find some more lightening grooves, in keeping with the rifles other lightened parts. Even the mock shell deflector has been hollowed, showing the level of thought APS has given to skirmishability when designing this rifle. At the rear of the receiver, the rifle features an ambidextrous charging handle, which retracts the mock bolt giving the user access to the adjustable hop-up. The Magwell has machined in finger grooves, providing an additional point of control when firing this AEG from unconventional positions and in tight spaces. The Trigger guard is enlarged and integrated into the lower receiver, reducing the number of possible failure points and strengthening the receiver over the standard AR15 design. The silver trigger denotes the eSilver gearbox inside, which we will drool over soon. The pistol grip features texturing on the front, rear and sides ensuring that you have a positive grip over the rifle in all conditions. The sliding stock is mounted to a 6 position AR15 buffer tube, offering a secure and modular stock mounting system and allowing a stock swap should you choose. The stock itself is a lightweight design, featuring two sling loops and a QD sling socket. The butt plate can be removed via a single pin giving access to the battery compartment inside the buffer tube.

The internal components of the PER Mark X are as impressive as its exterior. The APS eSilver gearbox features reinforcements in the shell itself, with APS adding extra material where standard gearboxes are known to fail. The gearbox features ball-bearing bushings, a bearing piston head, and a bearing spring guide, reducing wear and giving the gearbox its smooth, well-tuned sound. A far cry from the whine of some of the more affordable AEGs! The piston features full steel teeth and steel gears, adding to the robust nature of the reinforced gearbox. If you want to change your spring, APS have made it easy, all you have to do is remove the gearbox from the receiver and you can switch it out, without taking the gearbox apart! The internals also house a programmable FCU, offering the user the ability to program his or her trigger to suit the role.

 The Phantom Extremis is LiPo ready out of the box and features an extremely short trigger pull. I was genuinely shocked when testing it and I'm sure this feature alone will give you the upper hand in CQB. The rapid trigger response from the electronic trigger unit coupled with the short trigger pull will have this thing shooting as quickly as an HPA or GBBR rifle on semi, with the convenience of an electric power source. To top it all off the AEG has a tightbore 6.03mm inner barrel installed, giving unparalleled accuracy in such a small package."