Hi Luis, the warranty, if you want to call it that, is 10 days.
Used Guns: Customers have 10 calendar days from the date of transfer to request a return, unless the Buds Lifetime Warranty is purchased. BudsGunShop.com will accept a return on your used item for a full refund during this time frame if the item is malfunctioning. Shipping arrangements for the used item will be made solely at BudsGunShop.com discretion.

while the warranty is 10 days you can purchase a Buds Lifetime warranty for $21.00 during checkout

Hi Luis and welcome. Since the members here are customers as well, Buds Customer Service will be the best source for info on used firearms at 1-859-368-0371 9am-7pm EST Mon-Fri. or use the Blue Chat now button at the bottom right corner 9am to 7pm Mon - Sat and closed Sunday. Cheers and stay safe!