About a detective story catch phrase, '......had a brain you could drop thru the hole in a life saver...'

Question

the radio show is on sirius radio the radio classics channel. the show is titled 'philip marlow'. the character philip marlow is the one quoted as saying 'he looked like he had a brain you could drop through the hole in a life saver'. this is where i get confused because a life saver is a floatation device which slip over the head and down around the body. so whats special about being able to get ones head through it?

Answer 1

He's referring to the candy Lifesaver.