The Go!Link originally came out in 2004. As time went on some of the components we were using in the original design were no longer available, so the unit had to be redesigned to use new components. In Apr 2019 we updated the plastics in anticipation of the new model but continued to ship the original model, just with a different label. And then in May of 2019 we started shipping the redesigned model. The new model and the original should be identical as far as what it does, so you should be able to use them interchangeably. However, if you need to tell if the one you are using is the new model or the old one, look at the label on the back of the unit. In the lower left of the label the new model says “MODEL: GOL1920R2”, and the old model either says something else, or doesn’t say anything at all.

Released Model
2004 – 2019 4389-go-link_A_back.jpgNo text in the lower left.
Spring 2019 4389-go-link_C_back.jpgStill the 2004 electronics, but GOL1803R2 text in lower left.
2019 – Current 4389-go-link_D_back.jpgNew electronics, GOL1920R2 text in the lower left