Aero Precision, Upper Parts Kit, Anodized Finish, Black, Fits AR10 NEW WARNING Warning WARNING WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov. Forward Assist Assembly Forward Assist Spring Forward Assist Roll Pin Ejection Port Cover Door Ejection Port Cover Rod with c-clip Ejection Port Cover Spring Product Description Aero Precision's upper parts kit includes the parts you need to assemble your AR10 Upper Receiver.