What holds the back of the mower in place? One PL isn't going to keep the back of the mower from bouncing around. Yeah it's best to use 2 Fastraps. Considering the price, your getting two strap kits for the price of only one PL. I've only had to move the mower off a strap on two occasions. Both due to the wind blowing them in the way. Other then that, simply lay the straps where you want them and 9.9 times out of 10 they stay put while mowing. Try to get a PL to work on a Scag without having to spin the front caster around backwards to get them to work. Useless product in my eyes if it doesn't work on my mower or secure my mower from moving around.