TB stands for Team Buds. This is telling you that only Team Buds members can place the item on layaway.

TB is Team Buds it is a membership (like sams club) that give members added benefits lit the ability to buy and layaway certain high demand guns, used gun layaway and free layaways among other benefits the cost is $29.95 the 1st year the $24.95 thereafter checkout the benefits here and see if it is for you budsgunshop.com/teambuds.php If you do one 90 day layaway in the year you almost brake even 2 layaways and you are ahead