Springbok Mechanism (4e Feat)
From D&D Wiki
Springbok Mechanism [Racial]
Seeing a foe pass just out of reach, you prime the springs that are attached to your arms.
Benefit: When you make a weapon attack, you can choose to give your weapon the reach property for that attack. If you do, you take a -2 penalty to the attack roll. This has no effect on weapons that already have the reach property.