Standard Size: 240 X 200 X 40 mm (170 X 140 X 20 X 50) [(L * W* H) (l*w*h*s)] mm in which L = Length; W = Width; H= Edge Height; l= inner lenght; w: inner width; h = cradle height; s = neck rest slant height in milimeters. 
Contoured cradling and extra support / stability to patient's head in supine or other positions preventing risk of alopecia in opthalmic long tenured surgeries.
Extensive pressure redistribution for complete head rest.