Hi Luit, I checked your bulb on the book "The Genus Haemanthus", but your bulb doesn't fit the exact description of this species. Leaves narrowly ligulate (100-)150-350 mm long, 15-35(-40) mm wide....abaxial surface speckled with red towards the base, rarely immaculate...margin red, smooth or fringed with long soft hairs.
Maybe you can take the measures of your plant.
Ciao
Alberto