Specifications:

System Performance:
Modulation: FM
Carrier frequency: 914 MHz (USA) or 864 MHz (EU) (LPD band)

T 105 UHF Transmitter:
Switchable choice of three transmission frequencies:
863.175MHz, 863.500MHz, 863.900MHz
Power supply: 9 VDC, 200 mA
Weight: approx. 4.6 oz. (130 g)
Max. range: approx. 330 ft. (100 m)

K 105 UHF Headphones:
Power supply: 3 VDC (2 x 1.2 V AAA size NiCd rechargeable batteries supplied)
Battery life: approx. 10 hours (NiCd rechargeable batteries)
Frequency Response: 18 Hz to 20kHz
Max. SPL: >115 dB SPL
Distortion: <1%
Weight: approx. 7.8 oz. (220 g)
Type: semi-open dynamic headphones

Full AKG price list 

AKG Wireless Headphones

Affordable high quality headphones allowing freedom of movement. Supplied with rechargeable batteries, which last up to 10 hours. Runs from stereo headphone output or line output. Highly recommended in the Hi-Fi press.

Spare T105UHF transmitter and PSU available