Cadox M-50a VRN
Cadox M-50a VRN, Methyl ethyl ketone peroxide, CAS 1338-23-4, Organic peroxide, Cadox® M-50a VRN is a special purpose catalyst including a Vanishing Red Indicator System used for curing promoted unsaturated polyester resins at room temperature. This highly reactive catalyst provides a fast gel time and with a red indicating dye which allows the user to follow the cure by color.
https://www.nouryon.com/product/cadox-m-50a-vrn-methyl-ethyl-ketone-peroxide-cas-1338-23-4/