Yes, if you purchase the used 2018 Easton Ghost X Hyperlite -12 Senior League Baseball Bat: SL18GXHL12 you can use the bat during the 14 day guarantee and if you decide you don't like it for any reason, you can return it for a full refund or exchange.
With composite bats, like this 2018 Easton Ghost X Hyperlite -12 Senior League Baseball Bat (SL18GXHL12), we always recommend a break-in period.
On the first day of use, I would suggest taking roughly 100-150 swings off a tee, rotating the barrel a 1/4" every 15-20 swings. On the second day of use, I would recommend hitting soft tosses again, rotating the barrel every few swings. After doing this, the composite bat should be broken in!
The 2018 Easton Ghost X Hyperlite -12 Senior League Baseball Bat: SL18GXHL12 would be a one piece composite bat with a -12 length to weight ratio, so it will be a lighter bat overall than the 2017 Easton Mako Beast Senior League bat. The Mako Beast will also be a two piece composite bat, so less vibration will be felt on that bat than on the Ghost X Hyperlite.