STANDARD TYPES OF CONTACT BLOCK AND ASSEMBLY METHOD
Short contact block is available in 1a, 1b, 1a1b, 2a and 2b. The contact may be increased to 2a2b by replacing the short block with the long one. If more contacts are needed, just add the short one to the long one (The short one is not designed for being added by other block at its rear end). 3a, 3b, 3a3b, 4a and 4b will be available with one-long-oneshort blocks. By replacing the short block with another long one and becoming two-long blocks, 4a4b will be obtainable.