FATMAP difficulty grade
From the hut follow the path descending SW beneath the rocky buttress of the Hinter Allalin ridge to get onto the Hohlaub Glacier.
Go SSW across the Hohlaub Glacier passing under point 3150m to gain the Allalin Glacier.
Follow the R side of the glacier SW under the large cliffs to your R, negotiating your way round the crevasses, before the angle eases off around 3250m.
The route now heads L slightly, SW, avoiding a crevassed area beneath the Rimpfischhorn and climbs normally without undue difficulty to the Adlerpass, 3789m. From here, now suddenly with amazing views of the Zermatt giants, you follow the snowy ridge to the summit.
It passes a fore-summit at 3954m, where the slopes become wider.
Continue to the summit, which is a short rocky ridge, either via point 4128m, or via snowy slopes on the NW side.
Descent is the same in reverse.