This is Cleveland's 2012 Authentic on-field home alternate cap made by New Era. Cleveland introduced this cap in 2011 as an alternate home; it is based on the 2012 road cap, introduced as an alternate in 2008. Cleveland had not previously worn a red cap since the early 1970s. 

Cap is Authentic Collection 59FIFTY® which is the official on-field cap of Major League Baseball® and is worn by every Cleveland player. Made of 100% polyester, and designed with an embroidered (raised) Cleveland team logo on front and stitched Major League Baseball® logo on the rear. Interior includes branded taping as well as a CoolBase moisture wicking black sweatband. Fitted, closed back.

If you do not know your size: Determine where you want to wear your hat. Usually it is worn about an inch above the eyebrows and/or just above the ears. Have a friend hold the tape measure (cloth or plastic) at the point where you want the hat to rest on your head.  Insert the tip of your little finger between the tape and your head.  Record the measurement.  This should provide you with a comfortable fit.