I believe Garson hose uses a 1” thread but Garson hose id ranges from 1/2” to 3/4” for farming or industrial. this is an adapter for 1” Id hose. if you measure the size of your hose I’d, you can take two of my models on tinkercad and keep the one side and resize barb on other side and then center the two half’s from each model and join them to one piece and that should work. good luck, thanks for downloading!