Best kegels to get for pregnancy?

Kari • Hi! Kari's the name. Preggo with my second bundle of joy! Love muffin #1 was born March ‘17. 👶🏻
Four weeks pregnant and super surprised that kegels should be used.  Lol, never heard of that.  Any recommendations of the best type of kegels to get?   I use Amazon Prime all the time, so I'd like to purchase ASAP! 
Thanks for your help!