GRAS RA0238 Tapered Ear Canal Extension Kit for Kemar Pinna

GRAS RA0238 is a tapered ear canal extension for Kemar pinna with conical ear canals (VA-type).



The GRAS RA0238 is a tapered ear canal extension for the large (VA-type) Kemar pinna. It is for testing of insert-type ear phones and hearing aids.

It conforms with the provisions of the proposed revision of IEC 60318-7 (IEC CD 60318-7 © IEC 2015).


RA0238 is designed for use with the Kemar tapered (VA-style) pinnae, either the soft 35 Shore OO pair GRAS KB1090 and GRAS KB1091 or the harder 55 Shore OO pair GRAS KB0090 and GRAS KB1091.

It is made from stainless steel and will not deform when testing devices for use in the concha or pressed against the pinnae.

It has a 7.4 mm long pinna-extension tube, Ø 9.85 mm tapering down to 7.5 mm. The large diameter is for the junction towards the bottom of the concha, the small diameter is for the junction towards the occluded ear simulator.

The junctions will remain tight when the test object is inserted.

Applications and Use

RA0238 is primarily for use with Kemar fitted with tapered (VA-style) pinnae for testing of insert-type transducers.

The conical shape makes it easy to mount in-the-ear and completely-in-the-canal types of hearing aids and ear phones - without leakage and with good repeatability.

The tapered shape makes it easy to obtain good sealing during tests, and also ensures a perfect fit to the ear simulator at the one end and the pinna at the other.

Quality & Warranty

GRAS accessories are made of stainless steel, alloys and high-quality composites. These items are covered by a 2 year warranty respecting their intended use. On consumables like batteries, cables and windscreen we offer a 6 month warranty.

Ordering info

Optional items


KEMAR Large Right Ear 55 Shore OO (VA/SQ)


KEMAR Large Left Ear 55 Shore OO (VA/SQ)


KEMAR Large Right Ear 35 Shore OO (VA/SQ)


KEMAR Large Left Ear 35 Shore OO (VA/SQ)

GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.