Allora & Calzadilla, Unspecified Promise, 2017. American Black Granite, 1993 Caterpillar 416 Series Loader Backhoe. Collection of Institute of Contemporary Art, Miami. Museum purchase by Allora & Calzadilla Circle: Margot and George Greig, Helen Kent-Nicoll and Edward Nicoll, Ray Ellen and Allan Yarkin. Additional support from Barbara Z. Herzberg, Amy Dean and Alan Kluger.