Lax Vowels and Diphthongs

		Front	Central	Back
High	Lax	ɪ (it)		ʊ (put)
Mid	Lax	ɛ (pen)	ə (about) ʌ (but) ər (her)
Low	Lax	æ (hat)	a (hot) ay (my) aw (now)	ɔ (pot)(some dialects)

Sounds of American English

Merriam Webster Pronouncing Dictionary

Bartleby's Pronouncing Dictionary
(Includes Technical Words)

The Free Dictionary