There is a big differance between a 10 and a 20. The biggest ive heard of was 16". As I recall the worms were about $3-4+ each. The big problem is getting strikes where the fish holds the tail and you tear the worm up. I bought a bunch of 11" form some place in texas probably barlows, they were in bulk. I know Ive seem plastic worm molds in 12+. 16" is huge no need for 20. I even made big worm on the lathe but never got around to molding it in silicone. I want to say its 14" with a replacable tail and the tail was drawn around a spoon so its good size, may reduce strike from the tiny fish a tad. I used to have a bunch of berkley 12" worms, I did not like them at all. Also Basspro sells their own 12" worms, they are good. http://www.basspro.com/webapp/wcs/stores/servlet/Product_10151_-1_10001_15663_100007001_100000000_100007000_100-7-1