Good quality filter, built with German SCHOTT glass and installed in a strong and light metal ring.

The ND filter - Neutral Density - by K&F concept is built with an excellent German glass to which a multi-layer NANO coating has been applied (18 layers according to the manufacturer) which allow a light transmittance of 12.5% ​​and a reflectivity of 1.5%.
The glass also has an anti-scratch and waterproof coating which makes it ideal even in precarious weather situations.

The neutral density tint is well applied to the filter and has a smooth, well-balanced transition.

The outer ring is machined on numerical control machines. The feeling of grip is high and the rotation of the ring fluid; the latter is especially convenient during the positioning of the filter during shooting.

The neutrality in the filter is high and the images taken, even at long exposure, do not have color casts.

I bought the 58mm diameter version but there are various sizes on the market to adapt to your lenses.

The cost of the filter is € 39.99 in May 2021. Maybe a little high for the diameter in my possession but the quality of the glass is good.

I insert photos of the product. I hope my review will be useful for a possible future purchase. See you next review!