I agree with k18. The added sensation from the CR keeping you expanded may help you keep a firmer erection during sex but I have never had a CR keep me at 100%. The only thing I know that is guaranteed to give you 95 to 100% erection quality for sex is V, C or L. I have used different brands of CR to keep me expanded after a girth session, silicone and rubber and it works well for that. The silicone rings seem to work the best and are more durable. I have been looking at the Tantus premium CR and may order one of these