Bought these based off reviews and the modular design for travel. Love them, go together really well and you'd never know they aren't one piece They give really good flex and are a fast fin, I scissor kick in the water and used them in Qatar recently on a dive trip. They are comfortable and the build quality is fantastic. Love the adjustable heel straps and I chose a L-XL for a UK size 9, I've worn a 3mm and 5mm boot with no issues, yet to try them in my dry suit boots but suspect they will fit with no issues. Really easy to get on and off A big investment but great fins