Marathon Heater [India] Pvt. Ltd. Offers Heaters with Crimped on Leads. Marathon Heater [India] Pvt. Ltd. Manufactures Temperature Sensors, High Quality Heaters etc. The Heaters with Crimped on Leads are generally used where the temperature at the end of the heater exceeds the maximum rated temperature of the lead wire. The high temperature connectors are covered by 1-1/2" of 2500 volt silicone rubber coated fibreglass sleeving. The connection between the leads and power pins is made outside the heater; the unheated length at the lead end of the heater is kept to a minimum.