2 KHF2 (aq) → H2 (g) + F2 (g) + 2 KF (aq)
This is an oxidation-reduction (redox) reaction:
2 F-I - 2 e- → 2 F0 (oxidation)
2 HI + 2 e- → 2 H0 (reduction)
KHF2 is a reducing agent, KHF2 is an oxidizing agent.
This is a gas evolution reaction, H2 and F2 is the formed gas.