Well, I've had mine for a while and I have done enough with it for a basic rundown. I feel this is best in the electric guns section, as it closely resembles an AEG. When you get your engine, it will be in a box containing the FCU you need to wire to it, and a manual. It comes stock with a blue nozzle, which delivers field safe FPS almost certainly at higher PSI levels. The thing that confused me most is how FPS, air conservation, and RPS are adjusted with the polarstar. The FPS of your polarstar is a factor of PSI, poppet dwell, and nozzle colour. You'll want to increase your poppet flow to JUST at the level for your barrel length and BB weight, you want it to always shoot consistently by raising poppet dwell value. Once it is consistent, lower it until it is still consistent but at the lowest possible value. This makes your shots quieter, more air efficient, and accurate as possible. The RPS of your polarstar is affected by a value of your rate of fire measure, PSI and nozzle dwell. Raising nozzle dwell value helps feeding, but lowering it increases RoF, and therefore RoF ceiling at the highest RoF setting (1). So you might be confused about PSI still- well, I was too. Raising your PSI increases RoF AND FPS. Lowering it does the opposite. Changing the colour of your nozzle will increase your FPS at a given PSI (and therefore makes shooting at a given FPS more air efficient), but don't go jumping for a red nozzle yet. You'll need higher PSI if you want a higher RoF while maintaining a field legal FPS. Here's a rundown of the FCU and what every setting does! When you get your FCU, hook it up to deans if you want (I'm going to when I feel less lazy, it comes with tamiya), plug it in. It will say one of two things: SAFE or AUTO. If it says AUTO press in on the joystick to where it says SAFE. This disables firing and allows you to move the joystick to the sides to change between settings, up and down to adjust them. When you fire your gun, the AUTO display changes to something else, FIRE. FAFU: Full auto; scroll to 09-01. 09 is a 9 round burst, 01 makes your gun only able to shoot semi (1 round burst) DN: Nozzle Dwell; How long your nozzle stays retracted. Increasing this will allow more time for your BB to load and therefore fix jamming/misfeeding often, but will lower your RoF. DP: Poppet Dwell; How long the poppet releases air for. Increase this to the lowest value where you always shoot at a consistent FPS for your BB weight and barrel length. DR: Return to battery delay; I personally don't have it on mine, but I hear it has a similar effect to poppet dwell. DB: Debounce Threshold; Weird feature I don't use and can't see using PERSONALLY. I see the use for it though. When you pull the trigger, if you have DB at a value over 0, it will delay time until you've shot by an amount relative to your DB. Quite noticeable at higher values. RF: Rate of fire; Increase value to lower RoF, decrease value to a minimum of 1 to increase RoF CB: Closed bolt mode; It precocks your shot. Cool feature- for those who don't know what precocking is, it loads your BB into the hopup chamber before you take your shot. Some say this makes it more accurate, it's confirmed it lowers your trigger response though. You'll dry fire your first shot of every magazine. The polarstar can dry fire without any repercussions, so this is only a shot of annoyance on the field. Worth it always in my opinion. The EPAR (Electro-Pneumatic Airsoft Rifle, a gas gun with an onboard computer basically) is a system that has a lot of hype, but it has it's drawbacks. Here are a few points about the polarstar you won't get from common sense. -The hose is something every EPAR user has made a conscious decision to deal with, including me. The hose causes way more issues in reality then in theory. -If you have your FCU in a crane stock, say goodbye to a couple of the closer positions. Maybe with some finesse you can fix this. -There are a lot of fields who ban Polarstars due to the ability to change FPS. This is stupid considering with that logic they should ban G&G F2000s and ICS split gearbox guns, but logic doesn't seem to be the main sense of fieldowners. Check before you buy. -If you like working on gearboxes, finally getting a polarstar can be bittersweet because justifying other guns can be annoying afterwards. -You don't want multiple tanks, you have to regulate your shots or you'll find yourself running out of air depending on how long you play. Have a refill station nearby or watch the trigger. -I personally had to fully swap to a MOLLE system to accommodate my tank. -The largest problem of the polarstar is, in my opinion, the fact the poppet flow is way to high. I believe it was skag who told me he was discussing a low flow poppet with Polarstar, but it's not currently available to the public. This means you'll never find a BB heavy enough for your gun, .4s are too light. The optimal weight is .88 IIRC, but if you're firing ceramic/steel BBs it better not be at people. Note: Everything here is from my mind, the display of what it says when not safe/firing especially is bugging me that it could be wrong. If I missed anything, I'll correct when I find out about the mistake. Feel free to correct me on anything. Coming soon will be exact numbers with BB weight and brand, barrel length and bore, and approximate temperature and humidity. Also a build diary! Post your own and it will be copied on the front page with your credit. New WIPs: New way of tuning your DP, DR, and DN using lower settings to sacrifice FPS consistency for accuracy and efficiency, personal FCU settings, and of course the build diary. Chrono is on the way, I'll test exact FPS deviation as well as accuracy, comparing the new lowest possible DP with the old lowest possible DP while maintaining FPS consistency. Will update when I can.