The Pro-Mold slider boxes are preferred by many collectors over other manufacturer's boxes.  They feature an open "soap box" design that make it easy to access the cards while offering the same level of protection as other boxes.  In addition, the boxes hold securely closed and the bottoms don't fall out when you pick them up.  The Pro-Mold SB50 is sized to fit 25 normal sized trading cards.

Manufacturer's Description:
This plastic box will hold 50 regular trading cards. It features a precision fit, two-piece, soap dish design that has square corners in the bottom of it to keep the card's corners from fraying. This box is also used to hold many other different items besides trading cards as well.