Why buy one when the vet gives them out for free?? They also have the cork screw style tick tool but the tear drops work better in my opinion. Personally I don't use either, place your finger tip on the tick and rub it gently in a circular motion, within a minute (usually less than 30 seconds) the tick will release on it own and back out of the wound. I've removed countless ticks this way.
Edit: I have no idea why this works, but I was put onto this method 2 decades ago and have removed everyone since this way. no pulling required, no rick of leaving anything behind. YMMV