I think 'Speedlink SPES(SL-8691-SBK)' is cheap and small lapel mic.
So, I bought it.
7g | 3.5mm PLUG | 2.5m CABLE
Metal casing | Noise suppression | Clip
Package Contains : Clip-On Micro
System Requirements : PC or Mac
Impedance : 2.2kΩ
Sensitivity : -58dB ±3dB
Frequency Response : 100Hz to 15kHz
Weight : 7g
I think this mic's sensitivity is low. :-(
Plus, it's omni-directional.