Sennheiser MKE400  type_Optical Remote Not much larger than the

Not much larger than the standard 80mm lens

which doesn't notably affect usability (this is still the best Contax RF viewfinder available)

Old-school means that this lens still has a real aperture control ring

This is a powerful IR filter that will block near-IR and visible light

The Sony A55 is a DSLT camera with a 16mp APS-C sensor

Sennheiser MKE400 &nbsptype_Optical Remote Not much larger than theThe Sennheiser MKE400 is a compact, shoe mounted microphone with a foam cover and a removable "dead cat" windscreen (more like a dead rat in this case). Runs on a single AAA battery, connects via standard 1 8" miniplug. In excellent condition, with a small surface chunk of foam missing from the cover, which won't affect function.