Hitherto these grenades were imported by Army from Belgium and other countries (looking at older tenders). Also the Fuze contains batteries which are very difficult to make. Doing a ToT itself is not sufficient, neither for this nor for most defense products. For that matter incase of most of the batteries that HBL/HEB (the two large defence battery manufacturers) make the technoclogy/IP is available. BEL and ECIL with all the government backing and money still can’t make ‘artillery fuze’ batteries and rely on imports for the same.
HBL is only selling the Fuze and is an STE for the same, not the Grenade. CRPF/BSF tender was for grenade. The only reason HBL is STE is because no one else was able to develop the fuzes. MIL will bring in the rest of the components like upper body, explosive, propellant, cartridge case etc.