A fluid ejection device (100) includes a chamber (110), a first fluid channel (120) and a second fluid channel (122) each communicated with the chamber, a first peninsula (140) extended along the first fluid channel and a second peninsula (142) extended along the second fluid channel, and a first sidewall extended between the first peninsula and the chamber, and a second sidewall (152) extended between the second peninsula and the chamber. The first sidewall is oriented at a first angle (154) to the chamber and the second sidewall is oriented at a second angle (156) to the chamber such that the second angle is different from the first angle.