Snap-in Dunlop battery box black with snap-closed swing door for effects pedals using one 9 volt battery (accessed via the bottom of the pedal).
Cutout dimensions: 6,25 x 3,22 cm, box depth: 1,78 cm, snaps over a panel thickness of about 0,1 cm. Used on Dunlop Cry Baby Wah Wah GCB95 and many Dunlop effects pedals.