This is a sweet little clip on adapter to use Deckmate (Mechanism) accessories with your GPD Win 4 game system.  I print these with tough and heat resistant ABS filament.  It does clip on the far end of the exhaust port (like the LTE modem GPD sells for the win 4) but the ABS is guaranteed to not melt or deform (it's used for most injection molded plastic things you're used to).  Any other sellers selling similar adapters not using an industrial filament are selling adapters that will eventually deform and stop working...   My design also allows for full airflow into the back of the GPD Win 4. 

To install it clip the top on 1st, then the bottom and then push it into place.  Will attach very snugly and won't wiggle or come off unless you want it to.  To remove, pull straight out on the bottom to pop it off. 

Please Note: Orders shipped via USPS Priority Mail Express may be shipped via UPS 2nd Day Air, it's about the same costs and UPS is generally more reliable with quick shipping like this.