Wholesale Grav Labs 3" 25mm Glass Concentrate Taster - Assorted Colors 5/pk For the times you can't take your rig with you, there's the 12mm GRAV Concentrate Taster. This compact piece includes a glass arm and attached dish that's perfectly placed to use with plant extract. This 5 pack comes in assorted colors of glass so you can keep things fresh while you dab on the go