HD100 Headphones £21.86 plus £4.90 shipping@ Sennheiser Shop

At Sennheiser shop, the HD100 are reduced from £36.35 to £21.86, I wouldn't normally look at phones which are not over the ear, and although they are in the over the ear category, they are described as on the ear! However they look very lighweight and are pretty cheap by todays standards, so may be worth considering.
There are free returns.
Specifications Impedance 26 Ω
Frequency response (Headphones) 18–18,000 Hz (-10 dB)
Sound pressure level (SPL) 110 dB SPL @ 1 kHz, 1V RMS
THD, total harmonic distortion < 0.5 % (1 kHz, 100 dB SPL)
Ear coupling On-Ear
Jack plug 3.5mm angled plug
Cable length 1.4 m
Transducer principle Dynamic
Weight 113g
Acoustics Closed