Per multiple sources the wings have traded goal tender Petr Mrazek to the Flyers.
DET guaranteed no less than a 4th round for Mrazek. If PHI makes playoffs and Mrazek wins 5 games for PHI in reg season, 4th becomes a 3rd. If PHI advances to CF, and Mrazek wins six playoff games, the 3rd becomes a 2nd. If PHI re-signs him next season, DET gets PHI 3rd in 19.
So the minimum DET gets for Mrazek is a fourth-round pick, that could become a third- or a second-round pick, dependent on how Mrazek/Flyers perform. The additional pick, a third-rounder, is conditional only on Mrazek re-signing in PHI.