Here's how they're different:

LabelManager 150 is designed to be a desktop product AND fit easily in the palm of your hand. Just over eight ounces, it's ready to go with you, throughout your workspace. Features a spacious 13-character display and an ergonomically-designed keyboard with well-spaced oval keys for error-free use. Prints up to two lines in three fonts and seven print styles, with print preview - with our smear-proof thermal transfer technology.

Label compatibility: Prints three label widths: 1/4" (6 mm) , 3/8" (9 mm) and 1/2" (12 mm).

LabelManager 450 works independently - or with your PC and DYMO software - as a powerful electronic assistant on your file-related challenges and more. The LM450 combines cutting-edge design, unparalleled functionality, and economical thermal printing with features including an automatic cutter for added speed, typewriter-style keyboard with profiled keys for error-free use and an eye-saving LCD display with large characters. Produces barcodes in standalone mode and 17 different types of barcodes via the DYMO software, logos, graphics and all your favorite fonts on up to five lines per label in: five fonts, 15 sizes and 11 styles, with seven background patterns. Mirror-printing, plus much more.

Label compatibility: 1/4" (6 mm), 3/8" (9 mm), 1/2" (12 mm), 3/4" (19 mm) and 1" (24 mm).

LabelManager PCII is the electronic printer that's ideal for media labeling. It connects to your PC and its USB port, to let your imagination take hold - in the form of permanent, high-quality plastic labels up to 1" wide. Includes label design software for creating colorful, eye-catching labels from your favorite software programs - complete with text, bolds, italics, outlines, shadow, symbols and graphics for any medium you have. Also enables you to automatically date-and-time print on your media labels. Aligns left, centered and right.

Label compatibility: 1/4" (6 mm), 3/8" (9 mm) and 1/2" (12 mm), 3/4" (19 mm) and 1" (24 mm) D1 tapes.