A clip buckle assembly suitable for use in an animal collar has two releasably interlockable buckle members and an adjustment means having a tongue extending between a buckle member and a stop at the end of the tongue. The tongue is arranged to pass through a slider having a gripping means configurable between an open configuration, wherein the first tongue is free to slide through the first slider and a closed configuration, wherein the first tongue is held locked against the first slider when the first slider is urged in a slackening direction from the proximal towards the distal end of the first tongue, whereby the slider is arranged to be fixable against slackening at any of a plurality of positions along the first tongue. The stop is arranged to prevent the tongue from disengaging from the slider when the first slider is urged in the slackening direction.
