It isn't. The keys are actually double shot molded which is nice (unlike the 35S), but it's devoid of tactile feedback. Instead of any sort of spring, the keys

It isn't. The keys are actually double shot molded which is nice (unlike the 35S), but it's devoid of tactile feedback. Instead of any sort of spring, the keys sit on top of a sheet of foam with holes cut out for each key. Maybe this worked somewhat better when the calculators are new, my example was about 20 years old when I got it.