Two styles of ‘quarter-turn’ fasteners, using standard housings and fittings so they are interchangeable with key-operated models. Both are available in 19 mm & 30 mm lengths.
The ‘recess-square’ design allows relatively high turning force to be applied (using the 8 mm T-key). The ‘coin-op’ model is used as a convenient catch, opened with almost any coin or screwdriver blade.