Just channels, they both only do 16 satellites but can receive multiple signals.
Exactly the same size, just battery chipset and cost...
Mine
The compact size and practical design of the GPSlim240 makes it both easy to carryand also wearable across the chest , making the style-conscious user look even more stylish.
‧ Use SiRF StarIII chipset.
‧ 20-channel GPS Receiver for fast acquisition and reacguisition.
‧ 200,000 effective correlators for fast Time To First Fix(TTFF), even at poor satellite signal.
‧ Built-in WAAS/EGNOS Demodulator.
‧ Compatible with Bluetooth Serial Port Profile (SPP) completely
‧ Built-in rechargeable Lithium-ion battery for at least 8 hours operation.
‧ Built-in rechargeable battery for memory for RTC backup and fast Time To First Fix. (TTFF)
‧ Support NMEA0183 v2.2 data protocol or SiRF binary code.
‧ Provide expand terminal and can contact to other system without Bluetooth device.
M1200
Built in MTK MT3318 Low power consumption GPS chipset.
‧ 32 parallel satellite-tracking channels for fast acquisition and reacquisition.
‧ Superior sensitivity up to -159 dBm.
‧ Built-in WAAS/EGNOS Demodulator without any additional hardware. Or use the high-sensitive software to get the fast acquisition and reacquisition in the urban, canyon and foliage environments.
‧ Compatible with Bluetooth Serial Port Profile (SPP) completely.
‧ Low power consumption. Built-in rechargeable and changeable Lithium-ion battery, the working time can last 20 hours maximum.
‧ Provide expand terminal contact to other system without Bluetooth device.
‧ Support NMEA0183 V 3.01 data protocol
‧ 3 color-LEDs indicate to show the status of device.
‧ FLASH based program memory. New software revisions upgradeable through serial interface
‧ Small, sleek, and lightweight design easily fits in your hand.
‧ Over-Temperature protection
‧ Enhanced algorithms -SnapLock and SnapStart provide superior navigation, performance in urban, canyon and foliage environments.
‧ For Car navigation, Marine navigation, Fleet management, AVL, Personal navigation, Tracking System, and Mapping device application.