-Exclusively designed and safety tested to fit the following infant car seats: Nuna, Cybex, Maxi-Cosi, Clek -Compatible with WonderFold W2 Original +, W2 Elite/Luxe and all W4 Stroller Wagons. -Attaches to one side of the stroller wagon, leaving the other side open for a seat or bench seat -The adapter can rotate 360º at 90º intervals, allowing the car seat to face four directions. -Easy to install and folds with the stroller wagon. -Safety strap for added safety and stability. -Two car seat adapters may be installed on W4 models for Nuna, Cybex, Maxi-Cosi, Clek. Can also fit 2 on W2 models for UPPAbaby only. Both bench seats can be removed to accommodate two car seat adapters. -Only one car seat adapter may be installed on W2 models for Nuna, Cybex, Maxi-Cosi, Clek. -Car seats and stroller wagons NOT INCLUDED.