anyone bought these before? the first pic is available in qo100 while the 2nd pic available in shoppee. the sizes are different for these 2 after water filled. im confused which to get as i prefer a bigger one but the smaller one costs cheaper ($15 for 2) while qo100 is $18.90 for one, not including shipping yet. purpose of usage is for piles and it hurts..so wanna get one..