Glass Lid Features: 1) Excellent heat endurance: can withstand drastic temperature change (max. temp. 180o) 2) High surface hardness: 5 or 6 times of that of normal, hard to break, safe to use 3) Shape: round, oval, square and so on. 4) Diameter:12 - 36cm diameter (2cm increments), OEM welcomed 5) Thickness: 4mm, 5mm 6) Color: transparent, blue, green, your logo 7) With / without air hole 8)Can reach 250g / 1.5m impact test.