This adaptor will make your gas tm870 to hpa
you will need to make threds
2x m5 (one for the m4 gbb grip one for the tube in the backplate)
4x m3 (in the back plate)
you simply take off the hose on the cylender and replace it with a new flexible one. (6mm)
heat op the end that are going on the cylender and press it on.
then put your hpa grip on screw it to the m870 after that.
drill a hole to your m4 gbb grip.mount the m4 grip
put down the hose.
put on the back palte with 4x m3 hexscrews
then if you like mount a m4 stocktupe
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