Materials vary by style: the cozy black booties use fleece/faux shearling (often listed as 100% polyester), while the black rain boot styles use rubber or soft, flexible PVC.
Outsoles vary by style: rain boots use rubber outsoles, while fleece booties list polyester outsoles and often include non-skid bottoms for added traction.
Linings and insoles are typically polyester in the fleece styles, while rain-boot styles list rubber for lining and insoles.
The rain boots are described as 100% waterproof with a rubber/PVC upper, and they include pull-on loops to make putting them on and taking them off easier.
Supportive features include non-skid soles or non-skid bottoms and flexible soles that provide traction to help prevent slips for early walkers.
The fleece booties are described as made of soft fleece (noted as 100% polyester in some listings) and are explicitly said to keep a baby's feet warm.
