What is the extra slit next to thumb hole on my running jacket for

What is the extra slit next to thumb hole on my running jacket for? : r

Sparkhill80⚡️ (u/coshannonmarie) - Reddit

Loganupclose (u/loganupclose) - Reddit

What is the extra slit next to thumb hole on my running jacket for

Sparkhill80⚡️ (u/coshannonmarie) - Reddit

Sparkhill80⚡️ (u/coshannonmarie) - Reddit

Sparkhill80⚡️ (u/coshannonmarie) - Reddit

Sparkhill80⚡️ (u/coshannonmarie) - Reddit

What is the extra slit next to thumb hole on my running jacket for

What is the extra slit next to thumb hole on my running jacket for