On their website the oldest press release I can find (dated 7th April 2009) is about the U series and is reproduced below:
Clientron Corp., a global leading thin client provider, introduced its most space-saving, ultra-compact and stylish U series thin clients based on Intel Atom and VIA Eden ULV platform with fanless and ultra-low power design for today's green computing market.
Clientron U800 series, designed with Intel Atom TM N270 processor, and Intel 945GSE/ICH7-M chipset, is the new generation thin client platform that customers would benefit by the more powerful chipsets with sharp multimedia performance. U800 support DDR2 memory up to 1GB, one G-LAN, four USB 2.0 ports, one PS/2 connecter, one DVI output and audio ports.
Clientron U700 series, powered by VIA Eden NanoBGA2 400MHz processor and CN700 chipset, is the entry-level thin client can accommodate today's education, financial, government, healthcare, high-tech manufacturing and other industrial applications. Clientron U700 support DDR2 memory up to 1GHz, one LAN (10/100 Base T), four USB 2.0 ports, one PS/2 connecter, audio ports, and support VGA display modes and VESA mount.
The target OS platforms of these two models support Linux, Windows CE and Windows XP Embedded.
Moving on to 14th June 2010 Clientron announced the U720 series:
Clientron Corp., the top 1 independent thin client provider, introduced its the most space-saving, ultra-compact, fanless and stylish U720 thin client equipped with VIA VX855 chipset - an ultra power efficient, all-in-one chipset that addresses the key video performance and entertainment requirements of today's small form factor thin client.
Clientron U720 thin client powered by VIA Eden ULV 500MHz / 1GHz and VX855 chipset, featuring high performance 2D/3D graphics and powerful video graphic, supports DirectX 9.0 and a 128-bit 2D engine with hardware rotation capability. Additionally, support for all leading embedded operating systems including the forthcoming Microsoft Windows Embedded Standard 7 OS offers simple-to-use tools and embedded features that make development faster and cheaper.
U720 supports high-bandwidth DDR2 memory up to 2GB, and I/O connectors including one G-LAN, four USB 2.0 ports, one PS/2 connecter, one DVI-I output and audio ports. Benefit for its lower TCO and streamlined administrative management and security that U720 thin client is the best solution to replace traditional PCs for client-server based solutions.
The 10zig RBT-402 is a rebadged U700 - my example still carried the Clientron U700 label.
The current U720 series datasheet mentions 500MHz or 1GHz VIA Eden ULV processors and the physical appearance of the Dell FX130 made me think that it was an example of one of these. Disassembling it to get at the rear of the motherboard revealed the silk-screened legend: U720 V1.1 MADE IN CHINA.
The 10zig RBT616V, the Dell FX170 and the ChipPC EX-PC are examples of the U800 series.