Ares charging handle latch does not fit - it is much too small overall
Star trigger guard does not fit - the unit is about 1 mm too wide and the holes are too small for the KJ rolled pin to fit. modification may help, but the gaps and sharp edges left by fitting detract from the look. I'm using the standard trigger guard after trying to muscle it in (broke part of the receiver).
Ares tango down m4/m16 grip for GBB - does fit with minor modification - remove <1 mm of material from the inside of the grip to make it slip on easier. simple procedure to sand or dremel down (less than a minute with the dremel). bonus - no need to fill in a spot for the safety spring, the top is thick enough all-round.
G&P low profile gas block - fits with modification. it was tight sliding it onto the stock barrel and the KJ gas tube is about 1.5 to 2 mm larger than a standard aeg. Sand the inner portion of the block to fit on the barrel, and I elected to shave the gas tube down. alternatively you could drill out the hole in the gas block with an appropriate sized bit and a vice to hold it. some significant sanding of the corners was necessary to fit it inside a
Madbull DD omega rail (issue with Madbull/G&p, not a fault of KJ)
if I could go back in time i would order this
gas block as it fits the pins of the standard m4 barrel. my current set-up has the gas block being held be a grub screw and friction, its not going anywhere but it doesn't look perfect.