Strahlkraft has a new polymer which has been added which makes the rubber even more tacky and elastic. This also makes its pips very durable.
The rubber compound is somewhat soft but the shape of the pips makes the feeling of the rubber appear to be a little bit harder than it actually is. The ball trajectory it produces can be confusing and wobbly.
Strahlkraft is an option for advanced and professional players who prefer an active style of defending.