Crystal fruits or locally known as kasai (Pometia pinnata) and belongs to the same family as rambutan (Sapindaceae). I was told by locals that kasai fruits in Sarawak are smaller but taste equally nice. The fruit shown in the picture was bought from a fruit stall at Lundu. The fruit vendor informed me that the fruits is known as crystal fruit and was bought back from Papua New Guinea by a Sarawakian worker working in logging camps there. The fruits taste sweet which is similar to lychee.