Reeth 67mm healight plano-convex glass lenses, have different heights, they are separately 

diameter : 67mm , height : 27.7mm, edge thickness : 3.3mm

diameter : 67mm , height : 22mm, edge thickness : 3.4mm

diameter : 66.4mm , height : 28.6mm, edge thickness : 3.4mm

diameter : 66.8mm , height : 24.8mm, edge thickness : 3.5mm

diameter : 66.3mm , height : 25mm, edge thickness : 3.3mm

diameter : 66.7mm , height : 23.3mm, edge thickness : 3.3mm