It is about the size of a grain of rice and is called the stirrup.

它的大小大约是一粒米，被称为马镫。

youdao

The ivory Buddha carved by Shen Weizhong is the world's smallest piece of sculpture, its size being just four-fifths of a grain of rice.

沈为众雕刻的象牙佛像是世界上最小的雕刻，它只有一粒米的五分之四大。

youdao

The ivory Buddha carved by Shen Weizhong, a contemporary Chinese sculptor, is the world's smallest piece of sculpture, its size being just four-fifths that of a grain of rice.

中国当代雕刻工艺师沈为众雕刻的象牙佛像是世界上最小的雕刻。 这个象牙佛像只有一粒米的五分之四大。

《新英汉大辞典》

Since 2008 the United States has not sold a single grain of rice to Cuba.

VOA: standard.2010.07.29

The Philippines this week said it is cutting rice imports because of high prices, even though the country lost more than a million tons of grain to typhoons this year.

VOA: standard.2009.12.17

Anytime a black-eyed pea meets a grain of rice, it becomes Hoppin' John.

NPR: Vertamae's Hoppin' John

And have your vet inject your pet with a tiny microchip implant (it's about the size of a grain of rice).

CNN: Tips for road tripping with pets

Micro chipping involves a vet inserting a tiny device, about the size of a grain of rice, under the dog's skin.

CNN: Give a dog a cell phone