Available in  02 Sizes [Outer Diameter (X) * Inner Diameter (Y)* Thickness (Z) {in mm}] ~ Medium = [135 X 60 X 35] and; Large = [190 X 100 X 50]  in both green/ blue color options. 
Support's patient's head during surgery allow clear passage away for respiration anaesthetic pipes and other intubation from the bottom being without base
No pressure on eyes especially in prone position due to ergonomic design and elastomeric gel technology.