PC cards, CardBus and Expresscard slots

Physical Specifications

PCMCIA cards have one of the following standard physical dimensions:

Type I Card 54 mm by 85.6 mm by 3.3 mm

Type II Card 54 mm by 85.6 mm by 5 mm

Type III Card 54 mm by 85.6 mm by 10.5 mm

The PCMCIA card size is the same as a standard credit card except for thickness and corner rounding. Sometimes PCMCIA cards are referred to as credit-card memory or adapters.

Certain Toshiba notebook computers and other machines have a non-standard, oversized slot for which there are non-standard, oversized cards ranging from 14.5 millimeter (mm) to 16 mm (or more) thick. These cards and slots are sometimes incorrectly referred to as "Type IV." This size card will probably not become part of the PCMCIA standard.

A Type II card has the same thickness as a Type I card along the long sides and connector end; this provides mechanical compatibility. A bubble 0.85 mm thick on the top and bottom surfaces increases the card's total thickness to 5 mm. A Type III card has a additional 5.5 mm on the top surface bubble for a total thickness of 10.5 mm.

The standard allows a maximum card length of 135.6 mm, which means the card can extend outside the host. This accommodates bulky devices such as batteries, oversized connectors, removable media, transceivers, and the antenna required by some devices.

(Microsoft 2015)