Standard Size:  260 X 240 X 145 mm  [L * W* H] mm in which L = Length; W = Width and; H= Height  in milimeters. 
Support patient's head in prone position during prolonged surgeries
Protect head, neck and ears in prone position by complete pressure redistribution and ergonomic design allows ease of intubation.
PHR-III provides see through area at its bottom.