The AGM stands for “absorbed glass matt” which is what the battery plates are made of – a relatively new approach to building batteries & means they dont need topping up with water. This makes the battery safer to use & handle as it doesnt leak if tipped up the wrong way. This also brings the shipping cost down to a standard £11.99. Tested on our hire electric motors & they offered very good performance. A 40lb electric motor will draw about 40 amps per hour so this 100a/hr battery should easily offer 2 hours good running time. Dimensions 350 x 170 x 190 mm length by width x depth.