The AGM stands for “absorbed glass matt” which is what the battery plates are made of which – 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 fleet with electric motors & they offered good performance. Dimensions 270x 170 x 190 mm length by width x depth. There is a bigger 100 AH version too.