This was fine, have used the crest strips and much prefer those, although I know some people find them very irritating

This was expensive and I didn’t notice a difference really. 

I brought these for my husband as part as his birthday gift. He had kept mentioning them so I brought them. From what I can see and what he has said they work really well and are worth the money. 

I have used twice and have noticed a difference already! 

I have only used one and not noticed a massive difference