Turn your AAP-01 into a tactical tube dude. 

Note: Does not include the AAP-01 itself and will require an Upper Receiver Connector to properly fit such as this one: 
https://www.airsoftworld.net/action-army-aap-01-upper-receiver-connector-14mm-ccw-thread-adaptor.html
(I have no affiliation with the above retailer, it was just where I got mine forever ago. Feel free to shop elsewhere.)

This was a one-off 3D print in PLA using 30-40% infill so its sturdy but still lightweight. It was then sanded and painted with satin black paint.
Installation process is straight forward - install your own upper receiver connector, slide the upper receiver/'slide' cover all the way on, thread the suppressor all the way on, then install the charging handle cover using the screw I will provide. 

Also Note: Due to the nature of PLA plastic having a lower melting point than ABS, do not leave the parts close to a heat source such as the dashboard of your car on a sunny day, or on a glass patio table in the next 40 degree heatwave. It softens and warps the plastic.

Also also note: Its purely cosmetic. 

Free UK postage.