No measuring. Just roll in a ball, squeeze catalyst on topand knead! Made of a putty-like silicone, Otoform can be used for coveringburns, scars and other types of scars in splinting applications and compression treatments. Amount of catalyst paste controls setup time. Sets up at roomtemperature in 5 to 6 minutes. This versatile, all-around impression material is available in two sizes:170 and 800g. One catalyst is included with each size. Extra catalyst is available separately.