yes i have aquestion for you all . i can turn the discriminatog knob wide open , and in coin and jewerly , and it will give me a singial of a penny on a mashed beer can ,or a large pull tab , i have not yet seen where it will knock the pull tabs with the switch in the forward postion , i know that there is difference in pull tabs of the old kind and the new ones but this feature has not worked for me yet .i do not think it is working right , i have had it more than a year now have did ever kind of test on all kinds of metal;s and coins ,buttons you name it i have tried it /it has failed the test . have not tried at the beach . what do you all think .