The notebook memory slot diagnostic card is BD, and the desktop memory slot diagnostic card is DD. Only buying BD cannot be used because the code display is on the DD diagnostic card! The memory slot diagnostic card is basically compatible with all motherboards with memory slots, but for computers with only onboard memory, that is, motherboards without memory slots, you must use the V8 multi-function diagnostic card to cooperate! The memory slot diagnostic card has strong compatibility, and the DD diagnostic card can be compatible with desktop computers and all-in-one computers! BD can be compatible with computers of various brands, such as ordinary notebooks, for aliens, and for Apple MAC! Easy to use, no need to find various diagnostic interfaces on the motherboard! Old notebooks use DDR3 memory slots, such as for Lenovo E450. The memory diagnostic card cannot be inserted in parallel, and must be inserted into the motherboard memory slot at a 45-degree angle! type: computer diagnostic card Colour:Photo Color Material:plastic Package Contents: 1 x Diagnostic Test Card Set Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.