Thanks for your reply. I heard my electrician said that most other brands counter also can fit on it, as long as counting frequency rate is 3Hz and power supply is 24vdc, so I bought IVO NE134 to replace my old 1, but now the counter is on the press, when we start counting, the counter is running in uneven counting rate! for example: start from 1 2 3 4 5 6 7 and stucked on it until 3 -5 and then continue again, so every time we loose about 30%