1:material: PVC 5 standard most popular size to choose, for thick and thin rimless frame lens assemblies. For rimless eyeglasses prescription and reading eye lens frame assemblies requiring dual shaft sleeves This type of dual sleeve bushing has one hole on head of sleeves, can tighten up snug to lenses well. Standard Clear Color Plastic Bushings Size:(A)1.4mm x 7mm x 0.8mm; (B)1.5mm x 7mm x 0.8mm; (C)1.6mm x 7mm x 0.8mm(D)1.4mm x 7mm x 0.8mm with hole (E)1.5mm x 7mm x 0.8mm with hole