Good day,my friend. We are the professional manufacture of reflex Level gauge glass and transparent gauge glass & sight glass . our products have been exported to many countries,such as: USA,UK,GERMANY,MALAYSIA,PAKISTAN,JAPAN,KOREA,SPAIN,IRAN,MEXICO and so on. 1. Reflex gauge glass , Transparent flat gauge glass, TSL G/Glass size:500 x 34 (30) x 17 mm 400 x 34 (30) x 17 mm 370 x 34 (30) x 17 mm 340 x 34 (30) x 17 mm 320 x 34 (30) x 17 mm 300 x 34 (30) x 17 mm 280 x 34 (30) x 17 mm 250 x 34 (30) x 17 mm 218 x 34 (30) x 17 mm 190 x 34 (30) x 17 mm 165 x 34 (30) x 17 mm 140 x 34 (30) x 17 mm 115 x 34 (30) x 17 mm and so on. 2. sight glass: round, Rectangular & square , tubular sight glass , redline glass tube. size: according to requirements 3. material: pyrex glass, tempered soda lime glass, tempered borosilicate glass, tempered borosilicate 3.3, quartz. 4. packing: paper box, carton , plywood case. or according to requirement. 5. protective gasket:sealing gasket,graphite gasket,PTFE gasket,ceramic fiber gasket,mica shield . if you need, i can supply the free samples. welcome to visit our factory at any time. any questions, please feel free to contact with me, i will do my best. best regards,