The original canopys on the older zrc were made of polycarbonate(left over military stock bought at surplus)they would yellow over time,the new zrc have canopys made out of acrylic and are very clear,i had my new canopys made from acrylic super clear,cost around 4k,new ones made from poly around 10k,the poly is safer and less prone to cracking,most of the performance boats built on west coast use acrylic canopys