Kim I bought one and rode with it for a while. Its waterproof and can be easily removed. It does come with the straps to secure it but the straps are really for securing it to the BMW luggage rack which I bought when I bought the bag. I never tried to secure it to the seat behind me. I eventually sprung for the topcase because I wanted to stow my modular shoei helmet and it doesnt fit under the seat with the sena bluetooth attached. The topcase color matched though is like $1200 US dollars when its all said and done but I feel it is a better fit and look for my scooter.