Potent and selective monoacylglycerol lipase (MAGL) inhibitor. Blocks hydrolysis of the endocannabinoid 2-arachidonyl glycerol (2-AG) in vivo in the mouse brain (IC50 = 8 nM). Potentiates depolarization-induced suppression of excitability in cerebellar Purkinje neurons. Exhibits >300-fold selectivity for MAGL over FAAH in vitro.