Gruber speculum differs from other similar specula especially the politzer in that their tip is oval in shape. This shape has an advantage as it conforms more closely with that of the shape of the normal ear canal and hence they seat well inside the ear canal. Since this speculum is snugly fitting it cannot be rotated. Some surgeons beleive this to be a disadvantage because rotation movement facilitates introduction. It comes in three sizes.
size 1 (4mm x 5mm)
size 2 (5mm x 6mm)
size 3 (6mm x 7mm)
Image showing the shape of the tip of Gruber's speculum