I purchased the Apeks RK3 in pink. Size medium. I am a size 7 women’s and wear mares 5mm zip booties. The spring tongue allows me to slide my feet straight into the fin and it flicks up over my heel securing it firmly on my bootie without having to bend over, so good! They’re shorter so in a smaller boat they're not getting caught up in anything and anyone else's fins. Once they’re on and you’ll in the water they’re very light weight, I have not tested if they float completely but I can feel they’re much lighter. Very fast under the water compared to traditional fins. Spring back means easy on just as easy off. You can feel the quality in the rubber as soon as you pick them up. YOU WON’T REGRET THE PURCHASE OF THESE FINS. I CERTAINLY DON’T!!! Overall AMAZING