‘Wild! I can make that old bloke down there pick his nose again ... and again ... and again ...’
-- Ron Weasley (GF8)
Look like brass binoculars, except that they are covered in all sorts of weird knobs and dials; they are occasionally sold at Quidditch matches, such as the Quidditch World Cup. They can be set to replay action, zoom, slow down play, and overlay magical words that provide commentary in purple letters (GF7). They cost 10 Galleons at the Quidditch World Cup in 1994.
Harry buys them for himself, Ron & Hermione at the Quidditch World Cup (GF7). Ron thinks he has repaid Harry for them, and gets disappointed on learning that it was with leprechaun gold which disappears (GF28)
A combination of omniscient and binoculars
"omni" = "all"; "ocul" = "eye" (Latin)
Compare this to the cost of Harry's wand three years before, which only cost 7 Galleons (PS5), they seem quite expensive.