Hello everyone, i am new to this website and came to know about this from a friend. Do u people refer double engine to tortoise? what are the requirements for the turtle or tortoise to become a double engine? Every turtle will be having nails, how do u count the nails? how can we know that there are 20 nails r 12 nails? even i have a pet turtle in my fish tank, it have 20 nails. 3 in each leg r completely grown n visible clearly and other two in each leg are visible when it swim in water by stretching its claw. does it make a 20 nail r just 12 nail? its just a small one n weighs exactly 355gms. so is it gud for sale r not gud? i am totally confused with it? plz some one reply. i request admin to clear my doubt plz. waiting for ur replies. thank u