Nintendo have also released a small adaptor called the Universal Game Link Adapter (model DMG-14) which features a small second generation socket and a first generation plug. The adaptor can be used in conjunction with either the MGB-008 or the CGB-003 and features a thin plastic harness allowing it to be clipped on to either cable. In the USA and Europe Nintendo released the CGB-003 and DMG-14 as a set called the Universal Game Link Cable Set. As the set includes both the CGB-003 cable which features the smaller second generation connectors at both ends, plus a removable DMG-14 first generation adapter, it allows the connection of either two Game Boy Pocket/Colors, or one original Game Boy and one Game Boy Pocket/Color.
Source: Wikipedia, "Game Link Cable", available under the CC-BY-SA License.