The 1551 miniature plastic enclosure family from Hammond Manufacturing consists of 49 different sizes; in this latest extension to the range, a further 10 variants have been introduced. In addition to the available size and configuration options, a choice of colors, flanged lids, keyring, and USB C versions are also available. The 1551V ventilated sensor enclosure versions have now been extended with the addition of 1.77-, 2.13- and 3.15-inch (45, 60, and 80mm) diameter round versions, available with plain or vented covers. Also added to the 1551V range are unventilated cover versions of the 3.15 x 3.15, 2.36 x 2.36, 1.57 x 1.57 and 3.15 x 1.57 inch (80 x 80, 60 x 60, 40 x 40mm and 80 x 40mm) square and rectangular enclosures.

A key feature of the 1551V design is the snap-fit closure, which allows repeated opening and closing without tools and also maximizes the internal space for PCBs by eliminating screw fixings to secure the cover to the base. The internal real estate available for PCB mounting is 2.89 x 2.89, 2.13 x 2.13, 1.34 x 1.34 and 2.89 x 1.34 inch (74 x 74, 54 x 54, 34 x 34 and 74 x 34mm) in the rectangular units and 1.54, 2.13 and 2.89 inch (39, 54 and 73.50mm) in the circular ones. All options are available in black, grey, and white UL94-HB ABS as standard. All bases feature 0.16 inch (4mm) high PCB stand-offs, wall mounting slots, and a 15mm cable knockout.

All sizes are 0.79 inches (20mm) high, which gives enough space for board-mounted RJ45, USB, and other standard communication interfaces.