MAGscrape XL – Stainless Steel Blade for Glass (19 mm)
The stainless blade seems to remove a full 65mm width strip of algae from the glass with a single pass, whereas other blades that I have used in the past seem to miss patches and start to deteriorate after a few uses. This is a must for use aquatic shops too as it halves the cleaning time and gets into places that a normal magnet will not reach.