Unicon Concrete Products (H.K.) Limited was found in 1991 major in precast concrete units, precast concrete pipe, gully box and partition panel wall production. Factory located at Sheung Shui, Ho Sheung Heung and moved into Yuen Long Industrial Estate in 1992.

In 1998, Unicon realised infrastructure construction and housing demand in Hong Kong uprose substantially due to increase in population and construction industry increase in precast concrete units usage, the factory further relocated to Dong Guan, PRC for expansion. The factory in PRC is named Dong Guan Heng Li Hamker Precast Concrete Products Factory (Hamker) . The major products are precast facade units and various precast products for both public and private sector construction projects.

In the factory start up, Hamker acquired 20,000m2 of land and expanded to cover 60,000m2 in 2001. The factory consists several covered workshops and warehouses, steam curing facilities, two computer-controlled batching plants, climatic control laboratory, 11 nos. of (12.5~30 tones)gantry crane , 4 nos. of traverser and, 20 nos. of overhead crane for covered workshops and open space to facilitate all weather production.

In 1999, Hamker was successfully awarded the HKQAA ISO9000 accreditation and in 2006, we have also been awarded the ISO14001 certification for the ready mixed concrete and precast concrete units production. The manufacturing of concrete also fulfilled the requirement of QSPSC. In compliance with ISO9000, samples are sent to qualified HOKLAS laboratory in mainland and Hong Kong for testing and equipment calibration. Hamker also employ specialist to manage the daily operation in order to ensure the production quality achieve international standards.