Clone Any Part Quickly With Reprorubber. Made In U.S.A. Metrology Casting Material. Exotic Metrology-Grade Rubber - Self-Curing In Minutes Virtually Perfect Replica Casting Of Internal And External Forms Non-Toxic - Easy To Use - 100 Times Faster Than Rtv Silicones No Release Agent Is Ever Needed. Excellent For Checking Parts With Optical Comparators! Final Color - Light Blue Roll Two Equal-Sized Balls Of Catalyst Putty And Base Putty And Simply Knead Them Together Like Dough. Excellent For External Shapes. Simply Spread Over Master Pushing Down With Fingers And Wait For Cure 8-10 Minutes. You Have 3 Or 4 Minutes Of Manipulation Time. Therefore 14 Minutes Start To Finish. You Can Also Cast Internal Shapes And Cavities But Some Pressure Should Be Applied Such As A Weighted Object On Top.