I was looking for a travel/general purpose binocular light enough never to regret carrying, one that wouldn’t eventually wind up at the bottom of a drawer.
This weighs 365g which is, in my opinion, just short of the threshold of ‘heavy’ (400g and above).
It’s 9x magnification is a good compromise (holding a binocular properly steady with magnifications much over 10x takes practice and can become tiring).
The ‘28’ refers to the size of the objective lenses (the amount of light they admit); The larger the figure, the brighter the image, but also the larger and heavier the binoculars will be, as well as potentially more expensive.
These Pentax’s are very solid, clad in dark green rubber armour, are fully gas-filled and water-proof, and the optics are very close to top notch - you would have to spend more than double to see a relatively small improvement, but then you wouldn’t ever want to use them for fear of theft or damage……
I detect no colour fringing or other aberrations, colours are natural and unexaggerated, no excessive warmth (yellow cast) and resolution of very fine detail is of a very high order.
Finally, these have excellent ‘eye-relief’, which means if you wear spectacles, as I do, you get the full image and aren’t peering at 2 small circles in the tubes.
Strongly recommended.